def vasp_vol_relax():
Al = bulk('Al', 'fcc', a=4.5, cubic=True)
calc = Vasp(xc='LDA',
isif=7,
nsw=5,
ibrion=1,
ediffg=-1e-3,
lwave=False,
lcharg=False)
calc.calculate(Al)
# Explicitly parse atomic position output file from Vasp
CONTCAR_Al = io.read('CONTCAR', format='vasp')
print('Stress after relaxation:\n', calc.read_stress())
print('Al cell post relaxation from calc:\n', calc.get_atoms().get_cell())
print('Al cell post relaxation from atoms:\n', Al.get_cell())
print('Al cell post relaxation from CONTCAR:\n', CONTCAR_Al.get_cell())
# All the cells should be the same.
assert (calc.get_atoms().get_cell() == CONTCAR_Al.get_cell()).all()
assert (Al.get_cell() == CONTCAR_Al.get_cell()).all()
return Al
def test_vasp_relax():
slab = create_slab_with_constraints()
calc = Vasp(xc='LDA',
isif=0,
nsw=3,
ibrion=1,
ediffg=-1e-3,
lwave=False,
lcharg=False)
calc.calculate(slab)
init_slab = create_slab_with_constraints()
res = read('OUTCAR')
assert np.allclose(res.positions[0], init_slab.positions[0])
assert not np.allclose(res.positions[2], init_slab.positions[2])