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def test_surface_terminations():
from ase.build.surfaces_with_termination import surfaces_with_termination
from ase.build import surface
from ase.spacegroup import crystal
a = 4.6
c = 2.95
# Rutile:
rutile = crystal(['Ti', 'O'], basis=[(0, 0, 0), (0.3, 0.3, 0.0)],
spacegroup=136, cellpar=[a, a, c, 90, 90, 90])
slb = surface(rutile, indices=(1,1,0), layers=4, vacuum=10)
slb *= (1,2,1)
def check_surf_composition(images, formula):
for atoms in images:
zmax = atoms.positions[:, 2].max()
sym = atoms.symbols[abs(atoms.positions[:, 2] - zmax) < 1e-2]
red_formula, _ = sym.formula.reduce()
assert red_formula == formula
images = surfaces_with_termination(rutile,
indices=(1,1,0),
layers=4,
vacuum=10,
termination='O')
check_surf_composition(images, 'O')
images = surfaces_with_termination(rutile,
indices=(1,1,0),
layers=4,vacuum=10,
termination='TiO')
check_surf_composition(images, 'TiO')
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