No output of my first ase script

ASE
1

Hello Everyone,

I am trying to start my first ase script. I tried on a supercomputer cluster. I run the sctipt but nothing happened, only an error message suggesting the “ase.calculators.calculator.CalculatorSetupError: Vasp cannot handle non-periodic boundaries. Please enable all PBC, e.g. atoms.pbc=True”. I am quite confused. Would anyone please give me some advice. Thanks!

from ase import Atoms, Atom
from ase.calculators.vasp import Vasp
co = Atoms([Atom(‘C’, [0, 0, 0]),
Atom(‘O’, [1.2, 0, 0])],
cell=(6., 6., 6.))
calc = Vasp(xc=‘pbe’, # the exchange-correlation functional
encut=350, # planewave cutoff
atoms=co)
print(‘energy = {0} eV’.format(co.get_potential_energy()))
print(co.get_forces())

Error: Vasp cannot handle non-periodic boundaries. "
ase.calculators.calculator.CalculatorSetupError: Vasp cannot handle non-periodic boundaries. Please enable all PBC, e.g. atoms.pbc=True

2

At some point before calling co.get_potential_energy(), you need to set periodic boundary conditions (PBC) with co.pbc = True.