bands_Si.py

from ase.build.bulk import bulk
from ase.calculators.vasp import Vasp
from ase.dft.kpoints import bandpath
from ase.io import read
from ase.dft.band_structure import BandStructure

si = bulk('Si', 'diamond', a=5.4)
si.calc = Vasp(kpts=(4, 4, 4), xc='PBE', ediff=1e-6)
si.calc.clean()
si.get_potential_energy()

kpts, kcart, kcartspecial = bandpath('WLGXWK', si.cell, npoints=100)

si.calc.set(icharg=11, # Read charge density from CHGCAR
            lorbit=11,
            kpts=kpts,
            isym=-1,
            reciprocal=True)

si.get_potential_energy()

bs = BandStructure(read('vasprun.xml'))
bs.plot(emax=5.0, filename='bands_Si.pdf')