[gpaw-users] Trouble with spin-polarized calculation convergence NO molecule

[Clayborne, Penee A.]

Hello.  I am trying a spin polarized calculation for the NO molecule. However, after numerous attempts, I am having difficulty with the convergence.  Any recommendations?

from ase import *
from ase.all import *
from ase.optimize import QuasiNewton
from gpaw import GPAW, FermiDirac
from ase import Atoms
from ase.io import read, write, PickleTrajectory
from gpaw import *
import numpy
import numpy as np

atoms = read('NO.xyz')
atoms.center(vacuum=6.0)

calc = GPAW(h=0.18,
            maxiter=450,
            occupations=FermiDirac(0.05),
            spinpol=True,
            usesymm=False,
            charge=00.0,
            nbands=-20,
            xc='PBE',
            mixer=Mixer(0.2, 5),
            convergence={'energy':0.05, 'density':1.0e-5, 'eigenstates':1.0e-7},
           txt='NO.out')

atoms.set_calculator(calc)

traj = PickleTrajectory('NO.traj', 'w', atoms)

calc.set(convergence={'bands':-20})
e = atoms.get_potential_energy()

relax = QuasiNewton(atoms, trajectory='NO.traj')
relax.attach(traj.write)
relax.run(fmax=0.05)

write('relax_NO.xyz',atoms)
calc.write('NO.gpw', mode='all')

Thanks in advance!

P. Andre Clayborne, Ph.D.
Postdoctoral Appointee
Center for Nanoscale Materials
Argonne National Laboratory, Bldg. 440
Argonne, IL 60439