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# fmt: off
import pytest
from ase.build import bulk
from ase.utils import tokenize_version
@pytest.mark.skip('test is rather broken')
def test_dftb_bandstructure(dftb_factory):
# We need to get the DFTB+ version to know
# whether to skip this test or not.
# For this, we need to run DFTB+ and grep
# the version from the output header.
# cmd = os.environ['ASE_DFTB_COMMAND'].split()[0]
# cmd = dftb_factory.ex
version = dftb_factory.version()
if tokenize_version(version) < tokenize_version('17.1'):
pytest.skip('Band structure requires DFTB 17.1+')
calc = dftb_factory.calc(
label='dftb',
kpts=(3, 3, 3),
Hamiltonian_SCC='Yes',
Hamiltonian_SCCTolerance=1e-5,
Hamiltonian_MaxAngularMomentum_Si='d'
)
atoms = bulk('Si')
atoms.calc = calc
atoms.get_potential_energy()
efermi = calc.get_fermi_level()
assert abs(efermi - -2.90086680996455) < 1.
# DOS does not currently work because of
# missing "get_k_point_weights" function
# from ase.dft.dos import DOS
# dos = DOS(calc, width=0.2)
# d = dos.get_dos()
# e = dos.get_energies()
# print(d, e)
calc = dftb_factory.calc(
atoms=atoms,
label='dftb',
kpts={'path': 'WGXWLG', 'npoints': 50},
Hamiltonian_SCC='Yes',
Hamiltonian_MaxSCCIterations=1,
Hamiltonian_ReadInitialCharges='Yes',
Hamiltonian_MaxAngularMomentum_Si='d'
)
atoms.calc = calc
calc.calculate(atoms)
# calc.results['fermi_levels'] = [efermi]
calc.band_structure()
# Maybe write the band structure or assert something?
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