stacking_fault_static Input Terms

Calculation Metadata

Specifies metadata descriptors common to all calculation styles.

  • branch: A metadata group name that the calculation can be parsed by. Primarily meant for differentiating runs with different settings parameters.

LAMMPS and MPI Commands

Specifies the external commands for running LAMMPS and MPI.

  • lammps_command: The path to the executable for running LAMMPS on your system. Don’t include command line options.

  • mpi_command: The path to the MPI executable and any command line options to use for calling LAMMPS to run in parallel on your system. LAMMPS will run as a serial process if not given.

Interatomic Potential

Specifies the interatomic potential to use and the directory where any associated parameter files are located.

  • potential_file: The path to the potential_LAMMPS or potential_LAMMPS_KIM record that defines the interatomic potential to use for LAMMPS calculations.

  • potential_kim_id: If potential_file is a potential_LAMMPS_KIM record, this allows for the specification of which version of the KIM model to use by specifying a full kim model id. If not given, the newest known version of the kim model will be assumed.

  • potential_kim_potid: Some potential_LAMMPS_KIM records are associated with multiple potential entries. This allows for the clear specification of which potential (by potid) to associate with those kim models.This will affect the list of available symbols for the calculation.

  • potential_dir: The path to the directory containing any potential parameter files (eg. eam.alloy setfl files) that are needed for the potential. If not given, then any required files are expected to be in the working directory where the calculation is executed.

Initial System Configuration

Specifies the file and options to load for the initial atomic configuration.

  • load_file: The path to the initial configuration file to load.

  • load_style: The atomman.load() style indicating the format of the load_file.

  • load_options: A space-delimited list of key-value pairs for optional style-specific arguments used by atomman.load().

  • family: A metadata descriptor for relating the load_file back to the original crystal structure or prototype that the load_file was based on. If not given, will use the family field in load_file if load_style is ‘system_model’, or the file’s name otherwise.

  • symbols: A space-delimited list of the potential’s atom-model symbols to associate with the loaded system’s atom types. Required if load_file does not contain symbol/species information.

  • box_parameters: Specifies new box parameters to scale the loaded configuration by. Can be given either as a list of three or six numbers: ‘a b c’ for orthogonal boxes, or ‘a b c alpha beta gamma’ for triclinic boxes. The a, b, c parameters are in units of length and the alpha, beta, gamma angles are in degrees.

LAMMPS Energy/Force Minimization

Specifies the parameters and options associated with performing an energy and/or force minimization in LAMMPS.

  • energytolerance: The energy tolerance to use for the minimization. This value is unitless and corresponds to the etol term for the LAMMPS minimize command. Default value is 0.0.

  • forcetolerance: The force tolerance to use for the minimization. This value is in force units and corresponds to the ftol term for the LAMMPS minimize command. Default value is ‘0.0 eV/angstrom’.

  • maxiterations: The maximum number of iterations to use for the minimization. This value corresponds to the maxiter term for the LAMMPS minimize command. Default value is 100000.

  • maxevaluations: The maximum number of iterations to use for the minimization. This value corresponds to the maxeval term for the LAMMPS minimize command. Default value is 1000000.

  • maxatommotion: The maximum distance that any atom can move during a minimization iteration. This value is in units length and corresponds to the dmax term for the LAMMPS min_modify command. Default value is ‘0.01 angstrom’.

Stacking Fault

Specifies the parameter set that defines a stacking fault.

  • stackingfault_file: The path to a stacking_fault record file that collects the parameters associated with a specific stacking fault.

  • stackingfault_hkl: The Miller (hkl) plane for the fault plane given as three space-delimited integers.

  • stackingfault_a1vect_uvw: The Miller [uvw] vector to use for the a1 shift vector given as three space-delimited floats.

  • stackingfault_a2vect_uvw: The Miller [uvw] vector to use for the a2 shift vector given as three space-delimited floats.

  • stackingfault_cellsetting: The conventional cell setting to take stackingfault_hkl relative to if the loaded unit cell is a primitive cell. Allowed values are ‘p’, ‘c’, ‘i’, ‘a’, ‘b’ and ‘c’.

  • stackingfault_cutboxvector: Indicates which of the three box vectors (‘a’, ‘b’, or ‘c’) that the surface and fault planes will be made along. Default value is ‘c’.

  • stackingfault_shiftindex: A rigid body shift will be applied to the atoms such that the created surface plane will be halfway between two atomic planes. This is an integer value that changes which set of atomic planes that the plane is inserted between. Changing this effectively changes the termination planes.

  • stackingfault_faultpos_rel: A fractional coordinate from 0 to 1 indicating where along the cutboxvector to position the fault plane. Default value is 0.5, which if stackingfault_even is True will result in the same termination planes at the free surface and the stacking fault.

  • sizemults: Multiplication parameters to construct a supercell from the rotated system. Limited to three values for stacking fault generation.

  • stackingfault_minwidth: Specifies a mimimum width in length units that the system must be along the cutboxvector direction. The associated sizemult value will be increased if necessary to ensure this. Default value is 0.0.

  • stackingfault_even: If True, the number of replicas in the cutboxvector direction willbe even. Default value is False.

Input/Output Units

Specifies the default units to use for the other input keys and to use for saving to the results file.

  • length_unit: The unit of length to use. Default value is ‘angstrom’.

  • pressure_unit: The unit of pressure to use. Default value is ‘GPa’.

  • energy_unit: The unit of energy to use. Default value is ‘eV’.

  • force_unit: The unit of force to use. Default value is ‘eV/angstrom’.

Run Parameters

  • stackingfault_a1: The fractional shift to apply along the a1 direction.

  • stackingfault_a2: The fractional shift to apply along the a2 direction.