Example of elastic tensor calculation using VASP calculator and
elastic module.
'''
from ase.lattice.spacegroup import crystal
from parcalc import ClusterVasp, ParCalculate
from elastic import Crystal
import ase.units as units
from numpy import array, linspace
import matplotlib.pyplot as plt
import numpy
# Create the MgO crystal
a = 4.194
cryst = Crystal(
crystal(['Mg', 'O'], [(0, 0, 0), (0.5, 0.5, 0.5)],
spacegroup=225,
cellpar=[a, a, a, 90, 90, 90]))
# Create the calculator running on one, eight-core node.
# This is specific to the setup on my cluster.
# You have to adapt this part to your environment
calc = ClusterVasp(nodes=1, ppn=8)
# Assign the calculator to the crystal
cryst.set_calculator(calc)
# Set the calculation parameters
calc.set(prec='Accurate',
xc='PBE',
lreal=False,
nsw=30,
# Cubic
a = 4.194
crystals.append(
crystal(['Mg', 'O'], [(0, 0, 0), (0.5, 0.5, 0.5)],
spacegroup=225,
cellpar=[a, a, a, 90, 90, 90]))
# a = 4.194
# crystals.append(Crystal(crystal(['Ti', 'C'], [(0, 0, 0), (0.5, 0.5, 0.5)],
# spacegroup=225, cellpar=[a, a, a, 90, 90, 90])))
# Tetragonal
a = 4.60
c = 2.96
crystals.append(
Crystal(
crystal(['Ti', 'O'], [(0, 0, 0), (0.302, 0.302, 0)],
spacegroup=136,
cellpar=[a, a, c, 90, 90, 90])))
# Trigonal (this is metal - for sure the k spacing will be too small)
a = 4.48
c = 11.04
crystals.append(
Crystal(
crystal(['Sb'], [(0, 0, 0.24098)],
spacegroup=166,
cellpar=[a, a, c, 90, 90, 120])))
print("Running tests")
# Iterate over all crystals.
# We do not paralelize over test cases for clarity.
for cryst in crystals[:]: