MultilayerBuilder¶

class MultilayerBuilder(filename, object_id, layers, surface_vectors, relaxation_calculator=None, kpoint_density=None, relaxation_length=None, interaction_length=None, optimize_geometry_parameters=None, log_filename_prefix=None)¶

Constructor for the MultilayerBuilder object. A multilayer builder is a multilayer configuration composed of crystalline, amorphous, or vacuum layers. The lateral dimensions (a and b unit cell vectors) are specially chosen to minimize the strain while meeting certain constraints (e.g. minimum and maximum sizes).

The first crystal layer is taken to be the substrate, which is the layer that is unstrained.

Parameters:

filename (str) – The full or relative path to save the results to. See nlsave(). object_id (str) – The object id to use when saving. See nlsave(). layers (list of type CrystalLayer | AmorphousLayer | VacuumLayer) – The list of layers to create the multilayer builder from. There must be either one or two instances of CrystalLayers in the list. surface_vectors (PhysicalQuantity of type length) – The pair of vectors the define the lateral dimensions of the multilayer builder. The vectors may be given as 2d or 3d vectors, but the z components must be zero. If no surface vectors are given, then lowest strain surface vectors are selected automatically. relaxation_calculator (Calculator | None) – The calculator (typically DFT) to use when relaxing the atomic positions at the interfaces. If no additional relaxation is desired, then None can be given. Default: None kpoint_density (PhysicalQuantity of type length) – The target k-point sampling density. Default: 4.0 * Angstrom relaxation_length (PhysicalQuantity of type length) – The distance around the interfacial plane that is relaxed with the relaxation calculator. Default: 4.0 * Angstrom interaction_length (PhysicalQuantity of type length) – The distance around the interfacial plane within which atomic interactions will be included during the interface optimization. Default: 8.0 * Angstrom optimize_geometry_parameters (OptimizeGeometryParameters) – The optimize geometry parameters to use when optimizing the atoms at each interface. Note that restart_strategy does not have any effect since the restart mechanism within OptimizeGeometry() is disabled. Default: OptimizeGeometryParameters() log_filename_prefix (str or None) – Prefix for the filenames where the logging output for each calculation is stored. If a value of None is given then all logging output is done to stdout. Default: "multilayer_builder_"

blocks()¶

Returns:	A list of the block configurations.
Return type:	list of type BulkConfiguration

configuration()¶

Returns:	The multilayer builder configuration
Return type:	BulkConfiguration

filename()¶

Returns:	The filename where the study object is stored.
Return type:	str

interactionLength()¶

Returns:	The interaction length.
Return type:	PhysicalQuantity of type length

kpointDensity()¶

Returns:	The k-point density of the relaxation calculator.
Return type:	PhysicalQuantity of type length

layerIndices()¶

Returns:	A list containing the indices of each layer.
Return type:	list of type list of type int

layers()¶

Returns:	The layers of the multilayer builder.
Return type:	list of type CrystalLayer | AmorphousLayer | VacuumLayer

logFilenamePrefix()¶

Returns:	The filename prefix for the logging output of the study.
Return type:	str | LogToStdOut

materialSpecifications(**kwargs)¶

Parameters:	kwargs (dict) – A list of keyword arguments to pass to MaterialSpecifications. By default the relaxation_calculator will be used for the formation_energy_calculator, relaxation_calculator, and phonon_calculator. The optimize_geometry_parameters will default to the values passed to MultilayerBuilder. The supercell_repetitions defaults to (1, 1, 1). The pristine_configuration will be the multilayer configuration.
Returns:	The MaterialSpecifications for this multilayer configuration.
Return type:	MaterialSpecifications

nlprint(stream=None)¶

Print a string containing an ASCII table useful for plotting the Study object.

Parameters:	stream (python stream) – The stream the table should be written to. Default: NLPrintLogger()

numberOfProcessesPerTask()¶

Returns:	The number of processes to be used to execute each task. If None, all available processes should execute each task collaboratively.
Return type:	int | None

objectId()¶

Returns:	The name of the study object in the file.
Return type:	str

optimizeGeometryParameters()¶

Returns:	The optimize geometry parameters.
Return type:	OptimizeGeometryParameters

relaxationCalculator()¶

Returns:	The relaxation calculator.
Return type:	Calculator | None

relaxationLength()¶

Returns:	The relaxation length.
Return type:	PhysicalQuantity of type length

update()¶

Run the calculations for the study object.

layers = [
    CrystalLayer(
        MaterialSpecificationsDatabase.MULTILAYER_MATERIALS['Si (110)'],
        length=10.0*Angstrom
    ),
    AmorphousLayer(
        MaterialSpecificationsDatabase.MULTILAYER_MATERIALS['Silica'],
        length=10.0*Angstrom
    ),
    AmorphousLayer(
        MaterialSpecificationsDatabase.MULTILAYER_MATERIALS['Hafnia'],
        length=12.0*Angstrom
    ),
    CrystalLayer(
        MaterialSpecificationsDatabase.MULTILAYER_MATERIALS['Tungsten (111)'],
        length=10.0*Angstrom
    )
]

surface_vectors = [[-7.680028171823,  16.2918],
                   [ 7.680028171823,  10.8612]]*Angstrom

# Setup calculator used for optimizing interfaces.
relaxation_calculator = LCAOCalculator()