ASE Manual Release 3.6.1.2825 CAMd - CampOS Wiki

6.2.14 Partly occupied Wannier Functions
from ase.data.molecules import molecule
from gpaw import GPAW
atoms = molecule(’C6H6’)
atoms.center(vacuum=3.5)
calc = GPAW(h=.21, xc=’PBE’, txt=’benzene.txt’, nbands=18)
atoms.set_calculator(calc)
atoms.get_potential_energy()
calc.set(fixdensity=True, txt=’benzene-harris.txt’,
nbands=40, eigensolver=’cg’, convergence={’bands’: 35})
atoms.get_potential_energy()
calc.write(’benzene.gpw’, mode=’all’)
from gpaw import restart
from ase.dft import Wannier
atoms, calc = restart(’benzene.gpw’, txt=None)
# Make wannier functions of occupied space only
wan = Wannier(nwannier=15, calc=calc)
wan.localize()
for i in range(wan.nwannier):
wan.write_cube(i, ’benzene15_%i.cube’ % i)
# Make wannier functions using (three) extra degrees of freedom.
wan = Wannier(nwannier=18, calc=calc, fixedstates=15)
wan.localize()
wan.save(’wan18.pickle’)
for i in range(wan.nwannier):
wan.write_cube(i, ’benzene18_%i.cube’ % i)
from ase.dft import Wannier
from gpaw import restart
ASE Manual, Release 3.6.1.2828
atoms, calc = restart(’benzene.gpw’, txt=None)
wan = Wannier(nwannier=18, calc=calc, fixedstates=15, file=’wan18.pickle’)
import pylab as pl
weight_n = pl.sum(abs(wan.V_knw[0])**2, 1)
N = len(weight_n)
F = wan.fixedstates_k[0]
pl.figure(1, figsize=(12, 4))
pl.bar(range(1, N+1), weight_n, width=0.65, bottom=0,
color=’k’, edgecolor=’k’, linewidth=None,
align=’center’, orientation=’vertical’)
pl.plot([F+.5, F+.5], [0, 1], ’k--’)
pl.axis(xmin=.32, xmax=N+1.33, ymin=0, ymax=1)
pl.xlabel(’Eigenstate’)
pl.ylabel(’Projection of wannier functions’)
pl.savefig(’spectral_weight.png’)
pl.show()
import numpy as np
from ase import Atoms
from ase.dft.kpoints import monkhorst_pack
from gpaw import GPAW
6.2. ASE 43