calc_relax_static.py
Calculation script functions

process_input
(input_dict, UUID=None, build=True) Processes str input parameters, assigns default values if needed, and generates new, more complex terms as used by the calculation.
 Parameters
input_dict (dict) – Dictionary containing the calculation input parameters with string values. The allowed keys depends on the calculation style.
UUID (str, optional) – Unique identifier to use for the calculation instance. If not given and a ‘UUID’ key is not in input_dict, then a random UUID4 hash tag will be assigned.
build (bool, optional) – Indicates if all complex terms are to be built. A value of False allows for default values to be assigned even if some inputs required by the calculation are incomplete. (Default is True.)

relax_static
(lammps_command, system, potential, mpi_command=None, p_xx=0.0, p_yy=0.0, p_zz=0.0, p_xy=0.0, p_xz=0.0, p_yz=0.0, dispmult=0.0, etol=0.0, ftol=0.0, maxiter=10000, maxeval=100000, dmax=0.01, maxcycles=100, ctol=1e10) Repeatedly runs the ELASTIC example distributed with LAMMPS until box dimensions converge within a tolerance.
 Parameters
lammps_command (str) – Command for running LAMMPS.
system (atomman.System) – The system to perform the calculation on.
potential (atomman.lammps.Potential) – The LAMMPS implemented potential to use.
mpi_command (str, optional) – The MPI command for running LAMMPS in parallel. If not given, LAMMPS will run serially.
p_xx (float, optional) – The value to relax the x tensile pressure component to (default is 0.0).
p_yy (float, optional) – The value to relax the y tensile pressure component to (default is 0.0).
p_zz (float, optional) – The value to relax the z tensile pressure component to (default is 0.0).
p_xy (float, optional) – The value to relax the xy shear pressure component to (default is 0.0).
p_xz (float, optional) – The value to relax the xz shear pressure component to (default is 0.0).
p_yz (float, optional) – The value to relax the yz shear pressure component to (default is 0.0).
dispmult (float, optional) – Multiplier for applying a random displacement to all atomic positions prior to relaxing. Default value is 0.0.
etol (float, optional) – The energy tolerance for the structure minimization. This value is unitless. (Default is 0.0).
ftol (float, optional) – The force tolerance for the structure minimization. This value is in units of force. (Default is 0.0).
maxiter (int, optional) – The maximum number of minimization iterations to use (default is 10000).
maxeval (int, optional) – The maximum number of minimization evaluations to use (default is 100000).
dmax (float, optional) – The maximum distance in length units that any atom is allowed to relax in any direction during a single minimization iteration (default is 0.01 Angstroms).
pressure_unit (str, optional) – The unit of pressure to calculate the elastic constants in (default is ‘GPa’).
maxcycles (int, optional) – The maximum number of times the minimization algorithm is called. Default value is 100.
ctol (float, optional) – The relative tolerance used to determine if the lattice constants have converged (default is 1e10).
 Returns
Dictionary of results consisting of keys:
’relaxed_system’ (float)  The relaxed system.
’E_coh’ (float)  The cohesive energy of the relaxed system.
’measured_pxx’ (float)  The measured x tensile pressure of the relaxed system.
’measured_pyy’ (float)  The measured y tensile pressure of the relaxed system.
’measured_pzz’ (float)  The measured z tensile pressure of the relaxed system.
’measured_pxy’ (float)  The measured xy shear pressure of the relaxed system.
’measured_pxz’ (float)  The measured xz shear pressure of the relaxed system.
’measured_pyz’ (float)  The measured yz shear pressure of the relaxed system.
 Return type