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 ase_vol_relax(): Al = bulk('Al', 'fcc', a=4.5, cubic=True) calc = Vasp(xc='LDA') Al.set_calculator(calc) from ase.constraints import StrainFilter sf = StrainFilter(Al) qn = QuasiNewton(sf, logfile='relaxation.log') qn.run(fmax=0.1, steps=5) print('Stress:\n', calc.read_stress()) print('Al post ASE volume relaxation\n', calc.get_atoms().get_cell()) return Al