def wan(calc):
centers = [([0.125, 0.125, 0.125], 0, 1.5),
([0.125, 0.625, 0.125], 0, 1.5),
([0.125, 0.125, 0.625], 0, 1.5),
([0.625, 0.125, 0.125], 0, 1.5)]
w = Wannier(4, calc,
nbands=4,
verbose=False,
initialwannier=centers)
w.localize()
x = w.get_functional_value()
centers = (w.get_centers(1) * k) % 1
c = (centers - 0.125) * 2
#print w.get_radii() # broken! XXX
assert abs(c.round() - c).max() < 0.03
c = c.round().astype(int).tolist()
c.sort()
assert c == [[0, 0, 0], [0, 0, 1], [0, 1, 0], [1, 0, 0]]
if 0:
from ase.visualize import view
from ase import Atoms
watoms = calc.atoms + Atoms(symbols='X4',
scaled_positions=centers,
cell=calc.atoms.cell)
view(watoms)
return x
def test_get_centers():
# Rough test on the position of the Wannier functions' centers
gpaw = pytest.importorskip('gpaw')
calc = gpaw.GPAW(gpts=(32, 32, 32), nbands=4, txt=None)
atoms = molecule('H2', calculator=calc)
atoms.center(vacuum=3.)
atoms.get_potential_energy()
wanf = Wannier(nwannier=2, calc=calc, initialwannier='bloch')
centers = wanf.get_centers()
com = atoms.get_center_of_mass()
assert np.abs(centers - [com, com]).max() < 1e-4
