# Reference¶

## Command Line Interface (CLI)¶

Entry point module for the command-line

interface. The kmos executable should be on the program path, import this modules main function and run it.

To call kmos command as you would from the shell, use

kmos.cli.main('...')


Every command can be shortened as long as it is non-ambiguous, e.g.

kmos ex <xml-file>


kmos export <xml-file>


etc.

### List of commands¶

kmos benchmark
Run 1 mio. kMC steps on model in current directory and report runtime.
kmos build

Build kmc_model.so from *f90 files in the current directory.

-d/–debug
Turn on assertion statements in F90 code
-n/–no-compiler-optimization
Do not send optimizing flags to compiler.
kmos edit <xml-file>
Open the kmos xml-file in a GUI to edit the model.
kmos export <xml-file> [<export-path>]

Take a kmos xml-file and export all generated source code to the export-path. There try to build the kmc_model.so.

-s/--source-only
Export source only and don't build binary

-b/--backend (local_smart|lat_int)
Choose backend. Default is "local_smart".
lat_int is EXPERIMENTAL and not made
for production, yet.

-d/--debug
Turn on assertion statements in F90 code.
(Only active in compile step)

--acf
Build the modules base_acf.f90 and proclist_acf.f90. Default is false.
This both modules contain functions to calculate ACF (autocorrelation function) and MSD (mean squared displacement).

-n/--no-compiler-optimization
Do not send optimizing flags to compiler.

kmos help <command>
Print usage information for the given command.
kmos help all
Display documentation for all commands.
kmos import <xml-file>
Take a kmos xml-file and open an ipython shell with the project_tree imported as pt.
kmos rebuild

Export code and rebuild binary module from XML information included in kmc_settings.py in current directory.

-d/–debug
Turn on assertion statements in F90 code
kmos run
Open an interactive shell and create a KMC_Model in it
run == shell
kmos settings-export <xml-file> [<export-path>]
Take a kmos xml-file and export kmc_settings.py to the export-path.
kmos shell
Open an interactive shell and create a KMC_Model in it
run == shell
kmos version
Print version number and exit.
kmos view

Take a kmc_model.so and kmc_settings.py in the same directory and start to simulate the model visually.

-v/–steps-per-frame <number>
Number of steps per frame
kmos xml
Print xml representation of model to stdout

## Data Types¶

### kmos.types¶

Holds all the data models used in kmos.

class kmos.types.Project

A Project is where (almost) everything comes together. A Project holds all other elements needed to describe one kMC Project ready to be manipulated, exported, or imported.

The overall structure is the following as is also displayed in the editor GUI.

Project:

- Meta
- Parameters
- Lattice(s)
- Species
- Processes

add_layer(*layers, **kwargs)

Add a layer to the project. A Layer, or keywords that are passed to the Layer constructor are accepted.

Parameters: layers (list) – List of layers. cell (np.array (3x3)) – Size of unit-cell. default_layer (str.) – name of default layer.
add_parameter(*parameters, **kwargs)

Add a parameter to the project. A Parameter, or keywords that are passed to the Parameter constructor are accepted.

Parameters: name (str) – The name of the parameter. value (float) – Default value of parameter. adjustable (bool) – Create controller in GUI. min (float) – Minimum value for controller. max (float) – Maximum value for controller. scale (str) – Controller scale: ‘log’ or ‘lin’
add_process(*processes, **kwargs)

Add a process to the project. A Process, or keywords that are passed to the Process constructor are accepted.

Parameters: name (str) – Name of process. rate_constant (str) – Expression for rate constant. condition_list (list.) – List of conditions (class Condition). action_list (list.) – List of conditions (class Action). enabled (bool.) – Switch this process on or of. chemical_expression (str.) – Chemical expression (i.e: A@site1 + B@site2 -> empty@site1 + AB@site2) to generate process from. tof_count (dict.) – Stoichiometric factor for observable products {‘NH3’: 1, ‘H2O(gas)’: 2}. Hint: avoid space in keys.
add_site(**kwargs)

Add a site to the project. The arguments are

Parameters: name (str) – Name of layer to add the site to. site (Site) – Site instance to add.
add_species(*speciess, **kwargs)

Add a species to the project. A Species, or keywords that are passed to the Species constructor are accepted.

Parameters: name (str) – Name of species. color (str) – Color of species in editor GUI (#ffffff hex-type specification). representation (str) – ase.atoms.Atoms constructor describing species geometry. tags (str) – Tags of species (space separated string).
get_parameters(pattern=None)

Return list of parameters in Project.

Parameters: pattern (str) – Pattern to fnmatch name of parameter against.
get_processes(pattern=None)

Return list of processes.

Parameters: pattern (str) – Pattern to fnmatch name of process against.
get_speciess(pattern=None)

Return list of species in Project.

Parameters: pattern (str) – Pattern to fnmatch name of process against.
import_xml_file(filename)

Takes a filename, validates the content against kmc_project.dtd and import all fields into the current project tree

parse_and_add_process(string)

Generate and add processes using a shorthand notation like, e.g. :: process_name; species1A@coord1 + species2A@coord2 + ... -> species1B@coord1 + species2A@coord2 + ...; rate_constant_expression

.

Parameters: string (str) – shorthand notation for process
parse_process(string)

Generate processes using a shorthand notation like, e.g. :: process_name; species1A@coord1 + species2A@coord2 + ... -> species1B@coord1 + species2A@coord2 + ...; rate_constant_expression

.

Parameters: string (str) – shorthand notation for process
validate_model()

Run various consistency and completeness test of the model to make sure we have a minimally complete model.

class kmos.types.Meta(*args, **kwargs)

Class holding the meta-information about the kMC project

class kmos.types.Parameter(**kwargs)

A parameter that can be used in a rate constant expression and defined via some init file.

Parameters: name (str) – The name of the parameter. adjustable (bool) – Create controller in GUI. min (float) – Minimum value for controller. max (float) – Maximum value for controller. scale (str) – Controller scale: ‘log’ or ‘lin’
class kmos.types.LayerList(**kwargs)

A list of layers

Parameters: cell (np.array (3x3)) – Size of unit-cell. default_layer (str.) – name of default layer.
generate_coord(terms)

Expecting something of the form site_name.offset.layer and return a Coord object

generate_coord_set(size=[1, 1, 1], layer_name='default', site_name=None)

Generates a set of coordinates around unit cell of any desired size. By default it includes exactly all sites in the unit cell. By setting size=[2,1,1] one gets an additional set in the positive and negative x-direction.

class kmos.types.Layer(**kwargs)

Represents one layer in a possibly multi-layer geometry.

Parameters: name (str) – Name of layer. sites (list) – Sites associated with this layer (Default: [])
class kmos.types.Site(**kwargs)

Represents one lattice site.

Parameters: name (str) – Name of site. pos (np.array or str) – Position within unit cell. tags (str) – Tags for this site (space separated). default_species (str) – Initial population for this site.
class kmos.types.Species(**kwargs)

Class that represent a species such as oxygen, empty, ... . Note: empty is treated just like a species.

Parameters: name (str) – Name of species. color (str) – Color of species in editor GUI (#ffffff hex-type specification). representation (str) – ase.atoms.Atoms constructor describing species geometry. tags (str) – Tags of species (space separated string).
class kmos.types.Process(**kwargs)

One process in a kMC process list

Parameters: name (str) – Name of process. rate_constant (str) – Expression for rate constant. otf_rate (str) – Expression used to calculate rate on the fly using bystander’s configuration, otf backend only!. condition_list (list.) – List of conditions (class Condition). action_list (list.) – List of conditions (class Action). bystander_list (list.) – List of bystanders (class Bystander), otf backend only!. enabled (bool.) – Switch this process on or of. chemical_expression (str.) – Chemical expression (i.e: A@site1 + B@site2 -> empty@site1 + AB@site2) to generate process from. tof_count (dict.) – Stoichiometric factor for observable products {‘NH3’: 1, ‘H2Ogas’: 2}. Hint: avoid space in keys.
class kmos.types.ConditionAction(**kwargs)

Represents either a condition or an action. Since both have the same attributes we use the same class here, and just store them in different lists, depending on its role. For better readability one can also use Condition or Action which are just aliases.

Parameters: coord (Coord) – Relative Coord (generated by LayerList.generate_coord() or Lattice.generate_coord_set()). species (str) – Name of species.
class kmos.types.Coord(**kwargs)

Class that holds exactly one coordinate as used in the description of a process. The distinction between a Coord and a Site may seem superfluous but it is made to avoid data duplication.

Parameters: name (str) – Name of coordinate. offset (np.array or list) – Offset in term of unit-cells. layer (str) – Name of layer. tags (str) – List of tags (space separated string).
pos

pos is np.array((3, 1)) and is calculated from offset and position. Not to be set manually.

### kmos.io¶

Features front-end import/export functions for kMC Projects. Currently import and export is supported to XML and export is supported to Fortran 90 source code.

kmos.io.export_source(project_tree, export_dir=None, code_generator=None, options=None, accelerated=False)

Export a kmos project into Fortran 90 code that can be readily compiled using f2py. The model contained in project_tree will be stored under the directory export_dir. export_dir will be created if it does not exist. The XML representation of the model will be included in the kmc_settings.py module.

export_source is the central feature of the kmos approach. In order to generate different backend solvers, additional candidates of this methods could be implemented.

kmos.io.export_xml(project_tree, filename=None)

Writes a project to an XML file.

class kmos.io.ProcListWriter(data, dir)

Write the different parts of Fortran 90 code needed to run a kMC model.

write_proclist(smart=True, code_generator='local_smart', accelerated=False)

Write the proclist.f90 module, i.e. the rules which make up the kMC process list.

write_settings(code_generator='lat_int', accelerated=False)

Write the kmc_settings.py. This contains all parameters, which can be changed on the fly and without recompilation of the Fortran 90 modules.

## Editor frontend¶

### kmos.gui¶

A GUI frontend to create and edit kMC models.

class kmos.gui.Editor

The editor GUI frontend.

class kmos.gui.GTKProject(parent, menubar)

A facade of kmos.types.Project so that pygtk can display in a TreeView.

## Runtime frontend¶

### kmos.run¶

A front-end module to run a compiled kMC model. The actual model is imported in kmc_model.so and all parameters are stored in kmc_settings.py.

The model can be used directly like so:

from kmos.model import KMC_Model
model = KMC_Model()

model.parameters.T = 500
model.do_steps(100000)
model.view()


which, of course can also be part of a python script.

The model can also be run in a different process using the multiprocessing module. This mode is designed for use with a GUI so that the CPU intensive kMC integration can run at full throttle without impeding the front-end. Interaction with the model happens through Queues.

class kmos.run.ModelRunner

Setup and initiate many runs in parallel over a regular grid of parameters. A standard type of script is given below.

To allow execution from multiple hosts connected to the same filesystem calculated points are blocked via <classname>.lock. To redo a calculation <classname>.dat and <classname>.lock should be moved out of the way

from kmos.run import ModelRunner, PressureParameter, TemperatureParameter

class ScanKinetics(ModelRunner):
p_O2gas = PressureParameter(1)
T = TemperatureParameter(600)
p_COgas = PressureParameter(min=1, max=10, steps=40)
# ... other parameters to scan

ScanKinetics().run(init_steps=1e7, sample_steps=1e7, cores=4)

run(init_steps=100000000.0, sample_steps=100000000.0, cores=4, samples=1, random_seed=None)

Launch the ModelRunner instance. Creates a regular grid over all ModelParameters defined in the ModelRunner class.

Parameters: init_steps – Steps to run model before sampling (.ie. to reach steady-state).

(Default: 1e8) :type init_steps: int :param sample_steps: Number of steps to sample over (Default: 1e8) :type sample_steps: int :param cores: Number of parallel processes to launch. :type cores: int :param samples: Number of samples. Use more samples if precise coverages are needed (Default: 1). :type samples: int

class kmos.run.ModelParameter(min, max=None, steps=1, type=None, unit='')

A model parameter to be scanned. If instantiated with only one value this parameter will be fixed at this value.

Use a subclass for specific type of grid.

Parameters: min (float) – Minimum value for this parameter. max (float) – Maximum value for this parameter (Default: min) steps (int) – Number of steps between minimum and maximum.
class kmos.run.PressureParameter(*args, **kwargs)

Create a grid of p in [p_min, p_max] such that ln({p}) is a regular grid.

class kmos.run.TemperatureParameter(*args, **kwargs)

Create a grid of p in [T_min, T_max] such that ({T})**(-1) is a regular grid.

class kmos.run.LinearParameter(*args, **kwargs)

Create a regular grid between min and max.

class kmos.run.LogParameter(*args, **kwargs)

Create a log grid between 10^min and 10^max (like np.logspace)

class kmos.run.KMC_Model(image_queue=None, parameter_queue=None, signal_queue=None, size=None, system_name='kmc_model', banner=True, print_rates=False, autosend=True, steps_per_frame=50000, random_seed=None, cache_file=None, buffer_parameter=None, threshold_parameter=None, sampling_steps=None, execution_steps=None, save_limit=None)

API Front-end to initialize and run a kMC model using python bindings. Depending on the constructor call the model can be run either via directory calls or in a separate processes access via multiprocessing.Queues. Only one model instance can exist simultaneously per process.

_adjust_database()

Set the database of processes currently possible according to the current configuration.

_get_configuration()

Return current configuration of model.

Return type: np.array
_put(site, new_species, reduce=False)

Works exactly like put, but without updating the database of available processes. This is faster for when one does a lot updates at once, however one must call _adjust_database afterwards.

Examples

model._put([0,0,0,model.lattice.lattice_bridge], model.proclist.co])
# puts a CO molecule at the bridge site of the lower left unit cell

model._put([1,0,0,model.lattice.lattice_bridge], model.proclist.co ])
# puts a CO molecule at the bridge site one to the right

# ... many more


Parameters: site (list or np.array) – Site where to put the new species, i.e. [x, y, z, bridge] new_species (str) – Name of new species. reduce (bool) – Of periodic boundary conditions if site falls out site lattice (Default: False)
_set_configuration(config)

Set the current lattice configuration.

Expects a 4-dimensional array, with dimensions [X, Y, Z, N] where X, Y, Z are the lattice size and N the number of sites in each unit cell.

Parameters: config (np.array) – Configuration to set for model. Shape of array has to match with model size.
deallocate()

Deallocate all arrays that are allocated by the Fortran module. This needs to be called whenever more than one simulation is started from one process.

Note that the currenty state and history of the system is lost after calling this method.

Note: explicit invocation was chosen over the __del__ method because there seems to easy portable way to control garbage collection.

do_steps(n=10000, progress=False)

Propagate the model n steps.

Parameters: n (int) – Number of steps to run (Default: 10000)
double()

Double the size of the model in each direction and initialize larger model with current configuration in each copy.

dump_config(filename)

Use numpy mechanism to store current configuration in a file.

Parameters: filename (str) – Name of file, to write configuration to.
export_movie(frames=30, skip=1, prefix='movie', rotation='15z, -70x', suffix='png', verbose=False, **kwargs)
Export series of snapshots of model instance to an image

file in the current directory which allows for easy post-processing of images, e.g. using ffmpeg

avconv -i movie_%06d.png -r 24 movie.avi


or

ffmpeg -i movie_%06d.png -f image2 -r 24 movie.avi


Allows suffixes are png, pov, and eps. Additional keyword arguments (kwargs) are passed directly the ase.io.write of the ASE library.

When exporting to *.pov, one has to manually povray each *.pov file in the directory which is as simple as typing

for pov_file in *.pov
do
povray ${pov_file} done  using bash. param frames: Number of frames to records (Default: 30). int Number of kMC steps between frames (Default: 1). int Prefix for filename (Default: movie). :type #@ !—— A. Garhammer 2015—— #@ !subroutine update_clocks_acf(ran_time) #@ !****f* base/update_clocks_acf #@ ! FUNCTION #@ ! Updates walltime, kmc_step, kmc_step_acf, time_intervalls and kmc_time. #@ ! #@ ! ARGUMENTS #@ ! #@ ! * ran_time Random real number #@ !****** #@ !real(kind=rsingle), intent(in) :: ran_time #@ !real(kind=rsingle) :: runtime #@ #@ #@ ! Make sure ran_time is in the right interval #@ !ASSERT(ran_time.ge.0.,”base/update_clocks: ran_time variable has to be positive.”) #@ !ASSERT(ran_time.le.1.,”base/update_clocks: ran_time variable has to be less than 1.”) #@ #@ !kmc_time_step = -log(ran_time)/accum_rates(nr_of_proc) #@ ! Make sure the difference is not so small, that it is rounded off #@ ! ASSERT(kmc_time+kmc_time_step>kmc_time,”base/update_clocks: precision of kmc_time is not sufficient”) #@ #@ !call CPU_TIME(runtime) #@ #@ ! Make sure we are not dividing by zeroprefix: str param rotation: Angle from which movie is recorded (only useful if suffix is png). String to be interpreted by ASE (Default: ‘15x,-70x’) str File suffix (type) of exported file (Default: png). str get_atoms(geometry=True, tag=None, reset_time_overrun=False) Return an ASE Atoms object with additional information such as coverage and Turn-over-frequencies attached. The additional attributes are: • info (extra tags assigned to species) • kmc_step • kmc_time • occupation • procstat • integ_rates • tof_data tof_data contains previously defined TOFs in reaction per seconds per cell sampled since the last call to get_atoms() info can be used to better visualize similar looking molecule during post-processing procstat holds the number of times each process was executed since last get_atoms() call. Parameters: geometry (bool) – Return ASE object of current configuration (Default: True). get_backend() Return name of backend that model was compiled with. Return type: str get_occupation_header() Return the names of the fields returned by self.get_atoms().occupation. Useful for the header line of an ASCII output. get_param_header() Return the names of field return by self.get_atoms().params. Useful for the header line of an ASCII output. get_std_sampled_data(samples, sample_size, tof_method='integ', output='str', show_progress=False) Sample an average model and return TOFs and coverages in a standardized format : [parameters] [TOFs] [occupations] kmc_time kmc_step Parameter tof_method allows to switch between two different methods for evaluating turn-over-frequencies. The default method procstat evaluates the procstat counter, i.e. simply the number of executed events in the simulated time interval. integ will evaluate the number of times the reaction could be evaluated in the simulated time interval based on the local configurations and the rate constant. Credit for this latter method has to be given to Sebastian Matera for the idea and implementation. In each case check carefully that the observable is sampled good enough! Parameters: samples – Number of batches to average coverages over. sample_size (int) – Number of kMC steps in total. tof_method (str) – Method of how to sample TOFs. Possible values are procrates or integ. While procrates only counts the processes actually executed, integ evaluates the configuration to estimate the actual rates. The latter can be several orders more efficient for very slow processes. Differences resulting from the two methods can be used as on estimate for the statistical error in samples. get_tof_header() Return the names of the fields returned by self.get_atoms().tof_data. Useful for the header line of an ASCII output. halve() Halve the size of the model and initialize each site in the new model with a species randomly drawn from the sites that are reduced onto one. It is necessary that the simulation size is even. load_config(filename) Use numpy mechanism to load configuration from a file. User must ensure that size of stored configuration is correct. Parameters: filename (str) – Name of file, to write configuration to. nr2site(n) Accepts a site index and return the site in human readable coordinates. Parameters: n (int) – Index of site. str post_mortem(steps=None, propagate=False, err_code=None) Accepts an integer and generates a post-mortem report by running that many steps and returning which process would be executed next without executing it. Parameters: steps (int) – Number of steps to run before exit occurs (Default: None). propagate (bool) – Run this one more step, where error occurs (Default: False). err_code (str) – Error code generated by backend if project.meta.debug > 0 at compile time. print_accum_rate_summation(order='-rate', to_stdout=True) Shows rate individual processes contribute to the total rate The optional argument order can be one of: name, rate, rate_constant, nrofsites. You precede each keyword with a ‘-‘, to show in decreasing order. Default: ‘-rate’. Possible values are rate, rate_constant, name, nrofsites . print_adjustable_parameters(match=None, to_stdout=True) Print those methods that are adjustable via the GUI. Parameters: pattern (str) – fname pattern to limit the parameters. print_coverages(to_stdout=True) Show coverages (per unit cell) for each species and site type for current configurations. procstat_normalized(match=None) Print an overview view process names along with the number of times it has been executed divided by the current rate constant times the kmc time. Can help to find those processes which are kinetically hindered. Parameters: match (str) – fname pattern to filter matching parameter name. procstat_pprint(match=None) Print an overview view process names along with the number of times it has been executed. Parameters: match (str) – fname pattern to filter matching parameter name. put(site, new_species, reduce=False) Puts new_species at site. The site is given by 4-entry sequence like [x, y, z, n], where the first 3 entries define the unit cell from 0 to the number of unit cells in the respective direction. And n specifies the site within the unit cell. The database of available processes will be updated automatically. Examples model.put([0,0,0,model.lattice.site], model.proclist.co ]) # puts a CO molecule at the bridge site # of the lower left unit cell  Parameters: site (list or np.array) – Site where to put the new species, i.e. [x, y, z, bridge] new_species (str) – Name of new species. reduce (bool) – Of periodic boundary conditions if site falls out site lattice (Default: False) run() Runs the model indefinitely. To control the simulations, model must have been initialized with proper Queues. show(*args, **kwargs) Visualize the current configuration of the model using ASE ag. start() Start child process view() Start current model in live view mode. xml() Returns the XML representation that this model was created from. Return type: str class kmos.run.Model_Rate_Constants Holds all rate constants currently associated with the model. To inspect the expression and current settings of it you can just call it as a function with a (glob) pattern that matches the desired processes, e.g. model.rate_constant('*ads*')  could print all rate constants for adsorption. Given of course that ‘ads’ is part of the process name. The just get the rate constant for one specific process you can use model.rate_constant.by_name("<process name>")  To set rate constants manually use model.rate_constants.set("<pattern>", <rate-constant (expr.)>)  __call__(pattern=None, interactive=False, model=None) Return rate constants. Parameters: pattern (str) – fname pattern to filter matching parameter name. model (kmos Model) – runtime instance of kMC to extract rate constants from (optional) by_name(proc) Return rate constant currently set for proc Parameters: proc (str) – Name of process. inverse(interactive=False) Return inverse list of rate constants. class kmos.run.Model_Parameters(print_rates=True) Holds all user defined parameters of a model in concise form. All user defined parameters can be accessed and set as attributes, like so model.parameters.<parameter> = X.Y  __call__(match=None, interactive=False) Return parameters that match pattern’ Parameters: match (str) – fname pattern to filter matching parameter name. ### kmos.view¶ Run and view a kMC model. For this to work one needs a kmc_model.(so/pyd) and a kmc_settings.py in the import path. class kmos.view.KMC_Viewer(model=None, steps_per_frame=50000) A graphical front-end to run, manipulate and view a kMC model. exit(_widget, _event) Exit the viewer application cleanly killing all subprocesses before the main process. parameter_callback(name, value) Sent (updated) parameters to the model process. ### kmos.cli¶ Entry point module for the command-line interface. The kmos executable should be on the program path, import this modules main function and run it. To call kmos command as you would from the shell, use kmos.cli.main('...')  Every command can be shortened as long as it is non-ambiguous, e.g. kmos ex <xml-file>  instead of kmos export <xml-file>  etc. kmos.cli.main(args=None) The CLI main entry point function. The optional argument args, can be used to directly supply command line argument like$ kmos <args>

otherwise args will be taken from STDIN.

### kmos.utils¶

Several utility functions that do not seem to fit somewhere else.

kmos.utils.build(options)

Build binary with f2py binding from complete set of source file in the current directory.

kmos.utils.evaluate_kind_values(infile, outfile)

Go through a given file and dynamically replace all selected_int/real_kind calls with the dynamically evaluated fortran code using only code that the function itself contains.

kmos.utils.get_ase_constructor(atoms)

Return the ASE constructor string for atoms.

kmos.utils.split_sequence(seq, size)

Take a list and a number n and return list divided into n sublists of roughly equal size.

kmos.utils.write_py(fileobj, images, **kwargs)

Write a ASE atoms construction string for images into fileobj.

## kmos kMC project DTD¶

The central storage and exchange format is XML. XML was chosen over JSON, pickle or alike because it still seems as the most flexible and universal format with good methods to define the overall structure of the data.

One way to define an XML format is by using a document type description (DTD) and in fact at every import a kmos file is validated against the DTD below.

<!ELEMENT kmc (meta?,species_list?,parameter_list?, lattice, process_list?,output_list?)>
<!ATTLIST kmc
version CDATA #REQUIRED
>
<!ELEMENT meta EMPTY>
<!ATTLIST meta
author CDATA #IMPLIED
debug CDATA #IMPLIED
email CDATA #IMPLIED
model_dimension CDATA #IMPLIED
model_name CDATA #IMPLIED
>

<!ELEMENT species_list (species)*>
<!ATTLIST species_list
default_species CDATA #IMPLIED
>
<!ELEMENT species EMPTY>
<!ATTLIST species
name CDATA #REQUIRED
color CDATA #IMPLIED
representation CDATA #IMPLIED
tags CDATA #IMPLIED
>
<!ELEMENT parameter_list (parameter)*>
<!ELEMENT parameter EMPTY>
<!ATTLIST parameter
name CDATA #REQUIRED
value CDATA #IMPLIED
min CDATA #IMPLIED
max CDATA #IMPLIED
scale CDATA #IMPLIED
>
<!ELEMENT lattice (layer)*>
<!ATTLIST lattice
cell_size CDATA #REQUIRED
default_layer CDATA #REQUIRED
substrate_layer CDATA #IMPLIED
representation CDATA #IMPLIED
>
<!ELEMENT layer (site)*>
<!ATTLIST layer
name CDATA #REQUIRED
grid CDATA #IMPLIED
grid_offset CDATA #IMPLIED
color CDATA #IMPLIED
>
<!ELEMENT site EMPTY>
<!ATTLIST site
pos CDATA #REQUIRED
type CDATA #REQUIRED
tags CDATA #IMPLIED
default_species CDATA #IMPLIED
>
<!ELEMENT process_list (process)*>
<!ELEMENT process (condition|action)*>
<!ATTLIST process
name CDATA #REQUIRED
rate_constant CDATA #REQUIRED
enabled CDATA #IMPLIED
tof_count CDATA #IMPLIED
>
<!ELEMENT condition EMPTY>
<!ATTLIST condition
coord_name CDATA #REQUIRED
coord_layer CDATA #REQUIRED
coord_offset CDATA #REQUIRED
species CDATA #REQUIRED
implicit CDATA #IMPLIED
>
<!ELEMENT action EMPTY>
<!ATTLIST action
coord_name CDATA #REQUIRED
coord_layer CDATA #REQUIRED
coord_offset CDATA #REQUIRED
species CDATA #REQUIRED
>
<!ELEMENT output_list (output)*>
<!ELEMENT output EMPTY>
<!ATTLIST output
item CDATA #REQUIRED
>


## Backends¶

In general the backend includes all functions that are implemented in Fortran90, which therefore should not have to be changed by hand often. The backend is divided into three modules, which import each other in the following way

base <- lattice <- proclist


The key for this division is reusability of the code. The base module implement all aspects of the kMC code, which do not depend on the described model. Thus it “never” has to change. The latttice module basically repeats all methods of the base model in terms of lattice coordinates. Thus the lattice module only changes, when the geometry of the model changes, e.g. when you add or delete sites. The proclist module implements the process list, that is the species or states each site can have and the elementary steps. Typically that changes most often while developing a model.

The rate constants and physical parameters of the system are not implemented in the backend at all, since in the physical sense they are too high-level to justify encoding and compilation at the Fortran level and so they are typical read and parsed from a python script.

The kmos.run.KMC_Model class implements a convenient interface for most of these functions, however all public methods (in Fortran called subroutines) and variables can also be accessed directly like so

from kmos.run import KMC_Model
model = KMC_Model(print_rates=False, banner=False)
model.base.<TAB>
model.lattice.<TAB>
model.proclist.<TAB>


which works best in conjunction with ipython.

### local_smart¶

#### kmos/base¶

The base kMC module, which implements the kMC method on a lattice. Virtually any lattice kMC model can be build on top of this. The methods offered are:

• de/allocation of memory
• book-keeping of the lattice configuration and all available processes
• updating and tracking kMC time, kMC step and wall time
• determine the process and site to be executed
##### base/accum_rates¶
Stores the accumulated rate constant multiplied with the number of sites available for that process to be used by determine_procsite. Let be the rate constants the number of available sites, and the accumulated rates, then is calculated according to .

The main idea of this subroutine is described in del_proc. Adding one process to one capability is programmatically simpler since we can just add it to the end of the respective array in avail_sites.

• proc positive integer number that represents the process to be added.
• site positive integer number that represents the site to be manipulated
##### base/allocate_system¶

Allocates all book-keeping structures and stores local copies of system name and size(s):

• systen_name identifier of this simulation, used as name of punch file
• volume the total number of sites
• nr_of_proc the total number of processes
##### base/assertion_fail¶

Function that shall be used by all parts of the program to print a proper message in case some assertion fails.

• a condition that is supposed to hold true
• r message that is printed to the poor user in case it fails
##### base/avail_sites¶

Main book-keeping array that stores for each process the sites that are available and for each site the address in this very array. The meaning of the fields are:

avail_sites(proc, field, switch)

where:

• proc – refers to a process in the process list
• the field within the process, but the meaning differs as explained under ‘switch’
• switch – can be either 1 or 2 and switches between (1) the actual numbers of the sites, which are available and filled in from the left but in whatever order they come or (2) the location where the site is stored in (1).
##### base/can_do¶

Returns true if ‘site’ can do ‘proc’ right now

• proc integer representing the requested process.
• site integer representing the requested site.
• can writeable boolean, where the result will be stored.
##### base/deallocate_system¶

Deallocate all allocatable arrays: avail_sites, lattice, rates, accum_rates, integ_rates, procstat.

none

##### base/del_proc¶

del_proc delete one process from the main book-keeping array avail_sites. These book-keeping operations happen in O(1) time with the help of some more book-keeping overhead. avail_sites stores for each process all sites that are available. The array for each process is filled from the left, but sites generally not ordered. With this determine_procsite can effectively pick the next site and process. On the other hand a second array (avail_sites(:,:,2) ) holds for each process and each site, the location where it is stored in avail_site(:,:,1). If a site needs to be removed this subroutine first looks up the location via avail_sites(:,:,1) and replaces it with the site that is stored as the last element for this process.

• proc positive integer that states the process
• site positive integer that encodes the site to be manipulated
##### base/determine_procsite¶

Expects two random numbers between 0 and 1 and determines the corresponding process and site from accum_rates and avail_sites. Technically one random number would be sufficient but to circumvent issues with wrong interval_search_real implementation or rounding errors I decided to take two random numbers:

• ran_proc Random real number from that selects the next process
• ran_site Random real number from that selects the next site
• proc Return integer
• site Return integer
##### base/get_accum_rate¶

Return accumulated rate at a given process.

• proc_nr integer representing the requested process.
• return_accum_rate writeable real, where the requested accumulated rate will be stored.
##### base/get_avail_site¶

Return field from the avail_sites database

• proc_nr integer representing the requested process.
• field integer for the site at question
• switch 1 or 2 for site or storage location
##### base/get_integ_rate¶

Return integrated rate at a given process.

• proc_nr integer representing the requested process.
• return_integ_rate writeable real, where the requested integrated rate will be stored.
##### base/get_kmc_step¶

Return the current kmc_step

• kmc_step Writeable integer
##### base/get_kmc_time¶

Returns current kmc_time as rdouble real as defined in kind_values.f90.

• return_kmc_time writeable real, where the kmc_time will be stored.
##### base/get_kmc_time_step¶

Returns current kmc_time_step (the time increment).

• return_kmc_step writeable real, where the kmc_time_step will be stored.
##### base/get_kmc_volume¶

Return the total number of sites.

• volume Writeable integer.
##### base/get_nrofsites¶

Return how many sites are available for a certain process. Usually used for debugging

• proc integer representing the requested process
• return_nrofsites writeable integer, where nr of sites gets stored
##### base/get_procstat¶

Return process counter for process proc as integer.

• proc integer representing the requested process.
• return_procstat writeable integer, where the process counter will be stored.
##### base/get_rate¶

Return rate of given process.

• proc_nr integer representing the requested process.
• return_rate writeable real, where the requested rate will be stored.
##### base/get_species¶

Return the species that occupies site.

• site integer representing the site
##### base/get_system_name¶

Return the systems name, that was specified with base/allocate_system

• system_name Writeable string of type character(len=200).
##### base/get_walltime¶

Return the current walltime.

• return_walltime writeable real where the walltime will be stored.
##### base/increment_procstat¶

Increment the process counter for process proc by one.

• proc integer representing the process to be increment.
##### base/integ_rates¶
Stores the time-integrated rates (non-normalized to surface area) Used to determine reaction rates, i.e. average number of reactions per unit surface and time. Let the integrated rates, be the rate constants, the number of available sites during kMC-time interval i, the corresponding timesteps then at the time is calculated according to .
##### base/interval_search_real¶

This is basically a standard binary search algorithm that expects an array of ascending real numbers and a scalar real and return the key of the corresponding field, with the following modification :

• the value of the returned field is equal of larger of the given value. This is important because the given value is between 0 and the largest value in the array and otherwise the last field is never selected.
• if two or more values in the array are identical, the function return the index of the leftmost of those field. This is important because having field with identical values means that all field except the leftmost one do not contain any sites. Refer to update_accum_rate to understand why.
• the value of the returned field may no be zero. Therefore the index the to be equal or larger than the first non-zero field.

However: as everyone knows the binary search is trickier than it appears at first site especially real numbers. So intensive testing is suggested here!

• arr real array of type rsingle (kind_values.f90) in monotonically (not strictly) increasing order
• value real positive number from [0, max_arr_value]
##### base/kmc_step¶
Number of kMC steps executed.
##### base/kmc_time¶
Simulated kMC time in this run in seconds.
##### base/kmc_time_step¶
The time increment of the current kMC step.
##### base/lattice¶

Stores the actual physical lattice in a 1d array, where the value on each slot represents the species on that site.

Species constants can be conveniently defined in lattice_... and later used directly in the process list.

##### base/nr_of_proc¶
Total number of available processes.
##### base/nr_of_sites¶
Stores the number of sites available for each process.
##### base/procstat¶
Stores the total number of times each process has been executed during one simulation.
##### base/rates¶
Stores the rate constants for each process in s^-1.

Restore state of simulation from *.reload file as saved by save_system(). This function also allocates the system’s memory so calling allocate_system again, will cause a runtime failure.

• system_name string of 200 characters which will make the reload_system look for a file called ./<system_name>.reload
• reloaded logical return variable, that is .true. reload of system could be completed successfully, and .false. otherwise.
##### base/replace_species¶

Replaces the species at a given site with new_species, given that old_species is correct, i.e. identical to the site that is already there.

• site integer representing the site
• old_species integer representing the species to be removed
• new_species integer representing the species to be placed
##### base/reset_site¶

This function is a higher-level function to reset a site as if it never existed. To achieve this the species is set to null_species and all available processes are stripped from the site via del_proc.

• site integer representing the requested site.
• species integer representing the species that ought to be at the site, for consistency checks
##### base/save_system¶

save_system stores the entire system information in a simple ASCII filed names <system_name>.reload. All fields except avail_sites are stored in the simple scheme:

variable value

In the case of array variables, multiple values are seperated by one or more spaces, and the record is terminated with a newline. The variable avail_sites is treated slightly differently, since printed on a single line it is almost impossible to interpret from the ASCII files. Instead each process starts a new line, and the first number on the line stands for the process number and the remaining fields, hold the values.

none

##### base/set_kmc_time¶

Sets current kmc_time as rdouble real as defined in kind_values.f90.

• new readable real, that the kmc time will be set to
##### base/set_rate_const¶

Allows to set the rate constant of the process with the number proc_nr.

• proc_n The process number as defined in the corresponding proclist_ module.
• rate the rate in
##### base/set_system_name¶

Set the systems name. Useful in conjunction with base.save_system to save *.reload files under a different name than the default one.

• system_name Readable string of type character(len=200).
##### base/start_time¶
CPU time spent in simulation at least reload.
##### base/system_name¶
Unique indentifier of this simulation to be used for restart files. This name should not contain any characters that you don’t want to have in a filename either, i.e. only [A-Za-z0-9_-].
##### base/update_accum_rate¶

none

##### base/update_clocks¶

• ran_time Random real number
##### base/update_integ_rate¶

none

##### base/volume¶
Total number of sites.
##### base/walltime¶
Total CPU time spent on this simulation.

#### kmos/lattice¶

Implements the mappings between the real space lattice and the 1-D lattice, which kmos/base operates on. Furthermore replicates all geometry specific functions of kmos/base in terms of lattice coordinates. Using this module each site can be addressed with 4-tuple (i, j, k, n) where i, j, k define the unit cell and n the site within the unit cell.
##### lattice/allocate_system¶

Allocates system, fills mapping cache, and checks whether mapping is consistent

none

##### lattice/calculate_lattice2nr¶

Maps all lattice coordinates onto a continuous set of integer

• site integer array of size (4) a lattice coordinate
##### lattice/calculate_nr2lattice¶

Maps a continuous set of of integers to a 4-tuple representing a lattice coordinate

• nr integer representing the site index
##### lattice/deallocate_system¶

Deallocates system including mapping cache.

none

##### lattice/default_layer¶
The layer in which the model is initially in by default (only relevant for multi-lattice models).
##### lattice/lattice2nr¶
Caching array holding the mapping from index to lattice coordinate: (x, y, z, n) -> i.
##### lattice/model_dimension¶
Store the number of dimensions of this model: 1, 2, or 3
##### lattice/nr2lattice¶
Caching array holding the mapping from index to lattice coordinate: i -> (x, y, z, n).
##### lattice/nr_of_layers¶
Constant storing the number of layers (for multi-lattice models > 1)
##### lattice/site_positions¶
The positions of (adsorption) site in the unit cell in fractional coordinates.
##### lattice/spuck¶
spuck = Sites Per Unit Cell Konstant The number of sites per unit cell, i.e. for coordinate notation (x, y, n) this is the maximum value of n.
##### lattice/system_size¶

Stores the current size of the allocated system lattice (x, y, z) in an integer array. In low-dimensional system, corresponding entries will be set to 1. Note that this should be thought of as a read-only variable. Changing its value at model runtime will not the indented effect of actually changing the simulated lattice. The definitive location for custom lattice size is simulation_size in kmc_settings.py.

If the system size shall be changed programmatically, it needs to happen before the KMC_Model is instantiated and Fortran array are allocated accordingly, like to

#!/usr/bin/env python

import kmc_settings import kmos.run

kmc_settings.simulation_size = 9, 9, 4

with kmos.run.KMC_Model() as model:
print(model.lattice.system_size)))
##### lattice/unit_cell_size¶
The dimensions of the unit cell (e.g. in Angstrom) of the unit cell.

#### kmos/proclist¶

Implements the kMC process list.
##### proclist/do_kmc_step¶

Performs exactly one kMC step. * first update clock * then configuration sampling step * last execute process

none

##### proclist/do_kmc_steps¶

Performs n kMC step. If one has to run many steps without evaluation do_kmc_steps might perform a little better. * first update clock * then configuration sampling step * last execute process

n : Number of steps to run

##### proclist/get_kmc_step¶

Determines next step without executing it.

none

##### proclist/get_occupation¶

Evaluate current lattice configuration and returns the normalized occupation as matrix. Different species run along the first axis and different sites run along the second.

none

##### proclist/init¶
Allocates the system and initializes all sites in the given layer.
• input_system_size number of unit cell per axis.
• system_name identifier for reload file.
• layer initial layer.
• no_banner [optional] if True no copyright is issued.
##### proclist/initialize_state¶

Initialize all sites and book-keeping array for the given layer.

• layer integer representing layer
##### proclist/run_proc_nr¶

Runs process proc on site nr_site.

• proc integer representing the process number
• nr_site integer representing the site

#### libkmc/kind_values¶

This module offers kind_values for commonly used intrinsic types in a platform independent way.

### lat_int¶

#### kmos/base¶

The base kMC module, which implements the kMC method on a lattice. Virtually any lattice kMC model can be build on top of this. The methods offered are:

• de/allocation of memory
• book-keeping of the lattice configuration and all available processes
• updating and tracking kMC time, kMC step and wall time
• determine the process and site to be executed
##### base/accum_rates¶
Stores the accumulated rate constant multiplied with the number of sites available for that process to be used by determine_procsite. Let be the rate constants the number of available sites, and the accumulated rates, then is calculated according to .

The main idea of this subroutine is described in del_proc. Adding one process to one capability is programmatically simpler since we can just add it to the end of the respective array in avail_sites.

• proc positive integer number that represents the process to be added.
• site positive integer number that represents the site to be manipulated
##### base/allocate_system¶

Allocates all book-keeping structures and stores local copies of system name and size(s):

• systen_name identifier of this simulation, used as name of punch file
• volume the total number of sites
• nr_of_proc the total number of processes
##### base/assertion_fail¶

Function that shall be used by all parts of the program to print a proper message in case some assertion fails.

• a condition that is supposed to hold true
• r message that is printed to the poor user in case it fails
##### base/avail_sites¶

Main book-keeping array that stores for each process the sites that are available and for each site the address in this very array. The meaning of the fields are:

avail_sites(proc, field, switch)

where:

• proc – refers to a process in the process list
• the field within the process, but the meaning differs as explained under ‘switch’
• switch – can be either 1 or 2 and switches between (1) the actual numbers of the sites, which are available and filled in from the left but in whatever order they come or (2) the location where the site is stored in (1).
##### base/can_do¶

Returns true if ‘site’ can do ‘proc’ right now

• proc integer representing the requested process.
• site integer representing the requested site.
• can writeable boolean, where the result will be stored.
##### base/deallocate_system¶

Deallocate all allocatable arrays: avail_sites, lattice, rates, accum_rates, procstat.

none

##### base/del_proc¶

del_proc delete one process from the main book-keeping array avail_sites. These book-keeping operations happen in O(1) time with the help of some more book-keeping overhead. avail_sites stores for each process all sites that are available. The array for each process is filled from the left, but sites generally not ordered. With this determine_procsite can effectively pick the next site and process. On the other hand a second array (avail_sites(:,:,2) ) holds for each process and each site, the location where it is stored in avail_site(:,:,1). If a site needs to be removed this subroutine first looks up the location via avail_sites(:,:,1) and replaces it with the site that is stored as the last element for this process.

• proc positive integer that states the process
• site positive integer that encodes the site to be manipulated
##### base/determine_procsite¶

Expects two random numbers between 0 and 1 and determines the corresponding process and site from accum_rates and avail_sites. Technically one random number would be sufficient but to circumvent issues with wrong interval_search_real implementation or rounding errors I decided to take two random numbers:

• ran_proc Random real number from that selects the next process
• ran_site Random real number from that selects the next site
• proc Return integer
• site Return integer
##### base/get_accum_rate¶

Return accumulated rate at a given process.

• proc_nr integer representing the requested process.
• return_accum_rate writeable real, where the requested accumulated rate will be stored.
##### base/get_avail_site¶

Return field from the avail_sites database

• proc_nr integer representing the requested process.
• field integer for the site at question
• switch 1 or 2 for site or storage location
##### base/get_integ_rate¶

Return integrated rate at a given process.

• proc_nr integer representing the requested process.
• return_integ_rate writeable real, where the requested integrated rate will be stored.
##### base/get_kmc_step¶

Return the current kmc_step

• kmc_step Writeable integer
##### base/get_kmc_time¶

Returns current kmc_time as rdouble real as defined in kind_values.f90.

• return_kmc_time writeable real, where the kmc_time will be stored.
##### base/get_kmc_time_step¶

Returns current kmc_time_step (the time increment).

• return_kmc_step writeable integer, where the kmc_time_step will be stored.
##### base/get_kmc_volume¶

Return the total number of sites.

• volume Writeable integer.
##### base/get_nrofsites¶

Return how many sites are available for a certain process. Usually used for debugging

• proc integer representing the requested process
• return_nrofsites writeable integer, where nr of sites gets stored
##### base/get_procstat¶

Return process counter for process proc as integer.

• proc integer representing the requested process.
• return_procstat writeable integer, where the process counter will be stored.
##### base/get_rate¶

Return rate of given process.

• proc_nr integer representing the requested process.
• return_rate writeable real, where the requested rate will be stored.
##### base/get_species¶

Return the species that occupies site.

• site integer representing the site
##### base/get_system_name¶

Return the systems name, that was specified with base/allocate_system

• system_name Writeable string of type character(len=200).
##### base/get_walltime¶

Return the current walltime.

• return_walltime writeable real where the walltime will be stored.
##### base/increment_procstat¶

Increment the process counter for process proc by one.

• proc integer representing the process to be increment.
##### base/integ_rates¶
Stores the time-integrated rates (non-normalized to surface area) Used to determine reaction rates, i.e. average number of reactions per unit surface and time. Let the integrated rates, be the rate constants, the number of available sites during kMC-time interval i, the corresponding timesteps then at the time is calculated according to .
##### base/interval_search_real¶

This is basically a standard binary search algorithm that expects an array of ascending real numbers and a scalar real and return the key of the corresponding field, with the following modification :

• the value of the returned field is equal of larger of the given value. This is important because the given value is between 0 and the largest value in the array and otherwise the last field is never selected.
• if two or more values in the array are identical, the function return the index of the leftmost of those field. This is important because having field with identical values means that all field except the leftmost one do not contain any sites. Refer to update_accum_rate to understand why.
• the value of the returned field may no be zero. Therefore the index the to be equal or larger than the first non-zero field.

However: as everyone knows the binary search is trickier than it appears at first site especially real numbers. So intensive testing is suggested here!

• arr real array of type rsingle (kind_values.f90) in monotonically (not strictly) increasing order
• value real positive number from [0, max_arr_value]
##### base/kmc_step¶
Number of kMC steps executed.
##### base/kmc_time¶
Simulated kMC time in this run in seconds.
##### base/kmc_time_step¶
The time increment of the current kMC step.
##### base/lattice¶

Stores the actual physical lattice in a 1d array, where the value on each slot represents the species on that site.

Species constants can be conveniently defined in lattice_... and later used directly in the process list.

##### base/nr_of_proc¶
Total number of available processes.
##### base/nr_of_sites¶
Stores the number of sites available for each process.
##### base/procstat¶
Stores the total number of times each process has been executed during one simulation.
##### base/rates¶
Stores the rate constants for each process in s^-1.

Restore state of simulation from *.reload file as saved by save_system(). This function also allocates the system’s memory so calling allocate_system again, will cause a runtime failure.

• system_name string of 200 characters which will make the reload_system look for a file called ./<system_name>.reload
• reloaded logical return variable, that is .true. reload of system could be completed successfully, and .false. otherwise.
##### base/replace_species¶

Replaces the species at a given site with new_species, given that old_species is correct, i.e. identical to the site that is already there.

• site integer representing the site
• old_species integer representing the species to be removed
• new_species integer representing the species to be placed
##### base/reset_site¶

This function is a higher-level function to reset a site as if it never existed. To achieve this the species is set to null_species and all available processes are stripped from the site via del_proc.

• site integer representing the requested site.
• species integer representing the species that ought to be at the site, for consistency checks
##### base/save_system¶

save_system stores the entire system information in a simple ASCII filed names <system_name>.reload. All fields except avail_sites are stored in the simple scheme:

variable value

In the case of array variables, multiple values are seperated by one or more spaces, and the record is terminated with a newline. The variable avail_sites is treated slightly differently, since printed on a single line it is almost impossible to interpret from the ASCII files. Instead each process starts a new line, and the first number on the line stands for the process number and the remaining fields, hold the values.

none

##### base/set_kmc_time¶

Sets current kmc_time as rdouble real as defined in kind_values.f90.

• new readable real, that the kmc time will be set to
##### base/set_rate_const¶

Allows to set the rate constant of the process with the number proc_nr.

• proc_n The process number as defined in the corresponding proclist_ module.
• rate the rate in
##### base/set_system_name¶

Set the systems name. Useful in conjunction with base.save_system to save *.reload files under a different name than the default one.

• system_name Readable string of type character(len=200).
##### base/start_time¶
CPU time spent in simulation at least reload.
##### base/system_name¶
Unique indentifier of this simulation to be used for restart files. This name should not contain any characters that you don’t want to have in a filename either, i.e. only [A-Za-z0-9_-].
##### base/update_accum_rate¶

none

##### base/update_clocks¶

• ran_time Random real number
##### base/update_integ_rate¶

none

##### base/volume¶
Total number of sites.
##### base/walltime¶
Total CPU time spent on this simulation.

#### kmos/lattice¶

Implements the mappings between the real space lattice and the 1-D lattice, which kmos/base operates on. Furthermore replicates all geometry specific functions of kmos/base in terms of lattice coordinates. Using this module each site can be addressed with 4-tuple (i, j, k, n) where i, j, k define the unit cell and n the site within the unit cell.
##### lattice/allocate_system¶

Allocates system, fills mapping cache, and checks whether mapping is consistent

none

##### lattice/calculate_lattice2nr¶

Maps all lattice coordinates onto a continuous set of integer

• site integer array of size (4) a lattice coordinate
##### lattice/calculate_nr2lattice¶

Maps a continuous set of of integers to a 4-tuple representing a lattice coordinate

• nr integer representing the site index
##### lattice/deallocate_system¶

Deallocates system including mapping cache.

none

##### lattice/default_layer¶
The layer in which the model is initially in by default (only relevant for multi-lattice models).
##### lattice/lattice2nr¶
Caching array holding the mapping from index to lattice coordinate: (x, y, z, n) -> i.
##### lattice/model_dimension¶
Store the number of dimensions of this model: 1, 2, or 3
##### lattice/nr2lattice¶
Caching array holding the mapping from index to lattice coordinate: i -> (x, y, z, n).
##### lattice/nr_of_layers¶
Constant storing the number of layers (for multi-lattice models > 1)
##### lattice/site_positions¶
The positions of (adsorption) site in the unit cell in fractional coordinates.
##### lattice/spuck¶
spuck = Sites Per Unit Cell Konstant The number of sites per unit cell, i.e. for coordinate notation (x, y, n) this is the maximum value of n.
##### lattice/system_size¶

Stores the current size of the allocated system lattice (x, y, z) in an integer array. In low-dimensional system, corresponding entries will be set to 1. Note that this should be thought of as a read-only variable. Changing its value at model runtime will not the indented effect of actually changing the simulated lattice. The definitive location for custom lattice size is simulation_size in kmc_settings.py.

If the system size shall be changed programmatically, it needs to happen before the KMC_Model is instantiated and Fortran array are allocated accordingly, like to

#!/usr/bin/env python

import kmc_settings import kmos.run

kmc_settings.simulation_size = 9, 9, 4

with kmos.run.KMC_Model() as model:
print(model.lattice.system_size)))
##### lattice/unit_cell_size¶
The dimensions of the unit cell (e.g. in Angstrom) of the unit cell.

#### kmos/proclist¶

Implements the kMC process list.

#### proclist/do_kmc_step¶

Performs exactly one kMC step. * first update clock * then configuration sampling step * last execute process

none

##### proclist/do_kmc_steps¶

Performs n kMC step. If one has to run many steps without evaluation do_kmc_steps might perform a little better. * first update clock * then configuration sampling step * last execute process

n : Number of steps to run

##### proclist/get_kmc_step¶

Determines next step without executing it.

none

##### proclist/get_occupation¶

Evaluate current lattice configuration and returns the normalized occupation as matrix. Different species run along the first axis and different sites run along the second.

none

##### proclist/init¶
Allocates the system and initializes all sites in the given layer.
• input_system_size number of unit cell per axis.
• system_name identifier for reload file.
• layer initial layer.
• no_banner [optional] if True no copyright is issued.
##### proclist/initialize_state¶

Initialize all sites and book-keeping array for the given layer.

• layer integer representing layer

#### libkmc/kind_values¶

This module offers kind_values for commonly used intrinsic types in a platform independent way.

### otf¶

#### kmos/base¶

The base kMC module, which implements the kMC method on a lattice. Virtually any lattice kMC model can be build on top of this. The methods offered are:

• de/allocation of memory
• book-keeping of the lattice configuration and all available processes
• updating and tracking kMC time, kMC step and wall time
• determine the process and site to be executed
##### base/accum_rates¶
Stores the accumulated rate constant up to a given process number taking into account all sites in which it is possible. ###
##### base/accum_rates_proc¶
Used to store the accumulated rate associated to each process ###

The main idea of this subroutine is described in del_proc. Adding one process to one capability is programmatically simpler since we can just add it to the end of the respective array in avail_sites.

• proc positive integer number that represents the process to be added.
• site positive integer number that represents the site to be manipulated
##### base/allocate_system¶

Allocates all book-keeping structures and stores local copies of system name and size(s):

• systen_name identifier of this simulation, used as name of punch file
• volume the total number of sites
• nr_of_proc the total number of processes
##### base/assertion_fail¶

Function that shall be used by all parts of the program to print a proper message in case some assertion fails.

• a condition that is supposed to hold true
• r message that is printed to the poor user in case it fails
##### base/avail_sites¶

Main book-keeping array that stores for each process the sites that are available and for each site the address in this very array. The meaning of the fields are:

avail_sites(proc, field, switch)

where:

• proc – refers to a process in the process list
• the field within the process, but the meaning differs as explained under ‘switch’
• switch – can be either 1 or 2 and switches between (1) the actual numbers of the sites, which are available and filled in from the left but in whatever order they come or (2) the location where the site is stored in (1).
##### base/can_do¶

Returns true if ‘site’ can do ‘proc’ right now

• proc integer representing the requested process.
• site integer representing the requested site.
• can writeable boolean, where the result will be stored.
##### base/deallocate_system¶

Deallocate all allocatable arrays: avail_sites, lattice, rates, accum_rates, procstat.

none

##### base/del_proc¶

del_proc delete one process from the main book-keeping array avail_sites. These book-keeping operations happen in O(1) time with the help of some more book-keeping overhead. avail_sites stores for each process all sites that are available. The array for each process is filled from the left, but sites generally not ordered. With this determine_procsite can effectively pick the next site and process. On the other hand a second array (avail_sites(:,:,2) ) holds for each process and each site, the location where it is stored in avail_site(:,:,1). If a site needs to be removed this subroutine first looks up the location via avail_sites(:,:,1) and replaces it with the site that is stored as the last element for this process.

• proc positive integer that states the process
• site positive integer that encodes the site to be manipulated
##### base/determine_procsite¶

Expects two random numbers between 0 and 1 and determines the corresponding process and site from accum_rates and avail_sites. Technically one random number would be sufficient but to circumvent issues with wrong interval_search_real implementation or rounding errors I decided to take two random numbers:

• ran_proc Random real number from that selects the next process
• ran_site Random real number from that selects the next site
• proc Return integer
• site Return integer
##### base/get_accum_rate¶

Return accumulated rate at a given process.

• proc_nr integer representing the requested process.
• return_accum_rate writeable real, where the requested accumulated rate will be stored.
##### base/get_avail_site¶

Return field from the avail_sites database

• proc_nr integer representing the requested process.
• field integer for the site at question
• switch 1 or 2 for site or storage location
##### base/get_integ_rate¶

Return integrated rate at a given process.

• proc_nr integer representing the requested process.
• return_integ_rate writeable real, where the requested integrated rate will be stored.
##### base/get_kmc_step¶

Return the current kmc_step

• kmc_step Writeable integer
##### base/get_kmc_time¶

Returns current kmc_time as rdouble real as defined in kind_values.f90.

• return_kmc_time writeable real, where the kmc_time will be stored.
##### base/get_kmc_time_step¶

Returns current kmc_time_step (the time increment).

• return_kmc_step writeable integer, where the kmc_time_step will be stored.
##### base/get_kmc_volume¶

Return the total number of sites.

• volume Writeable integer.
##### base/get_nrofsites¶

Return how many sites are available for a certain process. Usually used for debugging

• proc integer representing the requested process
• return_nrofsites writeable integer, where nr of sites gets stored
##### base/get_procstat¶

Return process counter for process proc as integer.

• proc integer representing the requested process.
• return_procstat writeable integer, where the process counter will be stored.
##### base/get_rate¶

Return rate of given process.

• proc_nr integer representing the requested process.
• return_rate writeable real, where the requested rate will be stored.
##### base/get_species¶

Return the species that occupies site.

• site integer representing the site
##### base/get_system_name¶

Return the systems name, that was specified with base/allocate_system

• system_name Writeable string of type character(len=200).
##### base/get_walltime¶

Return the current walltime.

• return_walltime writeable real where the walltime will be stored.
##### base/increment_procstat¶

Increment the process counter for process proc by one.

• proc integer representing the process to be increment.
##### base/integ_rates¶
Stores the time-integrated rates (non-normalized to surface area) Used to determine reaction rates, i.e. average number of reactions per unit surface and time. Let the integrated rates, be the rate constants, the number of available sites during kMC-time interval i, the corresponding timesteps then at the time is calculated according to

System Message: WARNING/2 (a_{i}(t)=\sum_{i=1}} c_{i} n_{i}\Delta t_i)

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.
##### base/interval_search_real¶

This is basically a standard binary search algorithm that expects an array of ascending real numbers and a scalar real and return the key of the corresponding field, with the following modification :

• the value of the returned field is equal or larger than given value. This is important because the given value is between 0 and the largest value in the array and otherwise the last field is never selected.
• if two or more values in the array are identical, the function return the index of the leftmost of those field. This is important because having field with identical values means that all field except the leftmost one do not contain any sites. Refer to update_accum_rate to understand why.
• the value of the returned field may not be zero. Therefore the index the to be equal or larger than the first non-zero field.

However: as everyone knows the binary search is trickier than it appears at first sight especially real numbers. So intensive testing is suggested here!

• arr real array of type rsingle (kind_values.f90) in monotonically (not strictly) increasing order
• value real positive number from [0, max_arr_value]
##### base/kmc_step¶
Number of kMC steps executed.
##### base/kmc_time¶
Simulated kMC time in this run in seconds.
##### base/kmc_time_step¶
The time increment of the current kMC step.
##### base/lattice¶

Stores the actual physical lattice in a 1d array, where the value on each slot represents the species on that site.

Species constants can be conveniently defined in lattice_... and later used directly in the process list.

##### base/nr_of_proc¶
Total number of available processes.
##### base/nr_of_sites¶
Stores the number of sites available for each process.
##### base/procstat¶
Stores the total number of times each process has been executed during one simulation.
##### base/rates¶
Stores the rate constants for each currently possible process ordered as avail_sites(:,:,1).
##### base/rates¶
Stores the rate constants for each process in s^-1.
##### base/reaccumulate_rates_matrix¶
Performs a process wide reaccumulation of the values in the rates_matrix. To be used when some of the user parameters are updated. Expected to aleviate some of the problems arising from floating point errors

Restore state of simulation from *.reload file as saved by save_system(). This function also allocates the system’s memory so calling allocate_system again, will cause a runtime failure.

• system_name string of 200 characters which will make the reload_system look for a file called ./<system_name>.reload
• reloaded logical return variable, that is .true. reload of system could be completed successfully, and .false. otherwise.
##### base/replace_species¶

Replaces the species at a given site with new_species, given that old_species is correct, i.e. identical to the site that is already there.

• site integer representing the site
• old_species integer representing the species to be removed
• new_species integer representing the species to be placed
##### base/reset_site¶

This function is a higher-level function to reset a site as if it never existed. To achieve this the species is set to null_species and all available processes are stripped from the site via del_proc.

• site integer representing the requested site.
• species integer representing the species that ought to be at the site, for consistency checks
##### base/save_system¶

save_system stores the entire system information in a simple ASCII filed names <system_name>.reload. All fields except avail_sites are stored in the simple scheme:

variable value

In the case of array variables, multiple values are seperated by one or more spaces, and the record is terminated with a newline. The variable avail_sites is treated slightly differently, since printed on a single line it is almost impossible to interpret from the ASCII files. Instead each process starts a new line, and the first number on the line stands for the process number and the remaining fields, hold the values.

none

##### base/set_kmc_time¶

Sets current kmc_time as rdouble real as defined in kind_values.f90.

• new readable real, that the kmc time will be set to
##### base/set_rate_const¶

Allows to set the rate constant of the process with the number proc_nr.

• proc_n The process number as defined in the corresponding proclist_ module.
• rate the rate in
##### base/set_system_name¶

Set the systems name. Useful in conjunction with base.save_system to save *.reload files under a different name than the default one.

• system_name Readable string of type character(len=200).
##### base/start_time¶
CPU time spent in simulation at least reload.
##### base/system_name¶
Unique indentifier of this simulation to be used for restart files. This name should not contain any characters that you don’t want to have in a filename either, i.e. only [A-Za-z0-9_-].
##### base/update_accum_rate¶

none

##### base/update_clocks¶

• ran_time Random real number
##### base/update_integ_rate¶

none

##### base/update_rates_matrix¶

Updates the rates_matrix. To be used when the state of a bystander has been modified

!
• proc positive integer number that represents the process whose rate is changed.
• site positive integer number that represents the site for the process
• rate positive real number that represents the updated rate
##### base/volume¶
Total number of sites.
##### base/walltime¶
Total CPU time spent on this simulation.

#### kmos/lattice¶

Implements the mappings between the real space lattice and the 1-D lattice, which kmos/base operates on. Furthermore replicates all geometry specific functions of kmos/base in terms of lattice coordinates. Using this module each site can be addressed with 4-tuple (i, j, k, n) where i, j, k define the unit cell and n the site within the unit cell.
##### lattice/allocate_system¶

Allocates system, fills mapping cache, and checks whether mapping is consistent

none

##### lattice/calculate_lattice2nr¶

Maps all lattice coordinates onto a continuous set of integer

• site integer array of size (4) a lattice coordinate
##### lattice/calculate_nr2lattice¶

Maps a continuous set of of integers to a 4-tuple representing a lattice coordinate

• nr integer representing the site index
##### lattice/deallocate_system¶

Deallocates system including mapping cache.

none

##### lattice/default_layer¶
The layer in which the model is initially in by default (only relevant for multi-lattice models).
##### lattice/lattice2nr¶
Caching array holding the mapping from index to lattice coordinate: (x, y, z, n) -> i.
##### lattice/model_dimension¶
Store the number of dimensions of this model: 1, 2, or 3
##### lattice/nr2lattice¶
Caching array holding the mapping from index to lattice coordinate: i -> (x, y, z, n).
##### lattice/nr_of_layers¶
Constant storing the number of layers (for multi-lattice models > 1)
##### lattice/site_positions¶
The positions of (adsorption) site in the unit cell in fractional coordinates.
##### lattice/spuck¶
spuck = Sites Per Unit Cell Konstant The number of sites per unit cell, i.e. for coordinate notation (x, y, n) this is the maximum value of n.
##### lattice/system_size¶

Stores the current size of the allocated system lattice (x, y, z) in an integer array. In low-dimensional system, corresponding entries will be set to 1. Note that this should be thought of as a read-only variable. Changing its value at model runtime will not the indented effect of actually changing the simulated lattice. The definitive location for custom lattice size is simulation_size in kmc_settings.py.

If the system size shall be changed programmatically, it needs to happen before the KMC_Model is instantiated and Fortran array are allocated accordingly, like to

#!/usr/bin/env python

import kmc_settings import kmos.run

kmc_settings.simulation_size = 9, 9, 4

with kmos.run.KMC_Model() as model:
print(model.lattice.system_size)))
##### lattice/unit_cell_size¶
The dimensions of the unit cell (e.g. in Angstrom) of the unit cell.

#### kmos/proclist¶

Implements the kMC process list.

#### proclist/do_kmc_step¶

Performs exactly one kMC step. * first update clock * then configuration sampling step * last execute process

none

##### proclist/do_kmc_steps¶

Performs n kMC step. If one has to run many steps without evaluation do_kmc_steps might perform a little better. * first update clock * then configuration sampling step * last execute process

n : Number of steps to run

##### proclist/get_kmc_step¶

Determines next step without executing it.

none

##### proclist/get_occupation¶

Evaluate current lattice configuration and returns the normalized occupation as matrix. Different species run along the first axis and different sites run along the second.

none

##### proclist/init¶
Allocates the system and initializes all sites in the given layer.
• input_system_size number of unit cell per axis.
• system_name identifier for reload file.
• layer initial layer.
• no_banner [optional] if True no copyright is issued.
##### proclist/initialize_state¶

Initialize all sites and book-keeping array for the given layer.

• layer integer representing layer
##### proclist/run_proc_nr¶

Runs process proc on site nr_site.

• proc integer representing the process number
• nr_site` integer representing the site

#### libkmc/kind_values¶

This module offers kind_values for commonly used intrinsic types in a platform independent way.