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# fmt: off
import numpy as np
import pytest
from ase.cell import Cell
@pytest.fixture()
def cell():
return Cell([[1., 0., 0.],
[.1, 1., 0.],
[0., 0., 0.]])
def test_obl(cell):
"""Verify 2D Bravais lattice and band path versus pbc information."""
lat = cell.get_bravais_lattice()
print(cell.cellpar())
print(lat)
assert lat.name == 'OBL'
def test_mcl_obl(cell):
cell[2, 2] = 7
lat3d = cell.get_bravais_lattice()
print(lat3d)
assert lat3d.name == 'MCL'
lat2d_pbc = cell.get_bravais_lattice(pbc=[1, 1, 0])
print(lat2d_pbc)
assert lat2d_pbc.name == 'OBL'
path = cell.bandpath()
print(path)
path2d = cell.bandpath(pbc=[1, 1, 0])
print(path2d)
assert path2d.cell.rank == 2
assert path2d.cell.get_bravais_lattice().name == 'OBL'
@pytest.mark.parametrize('angle', [60, 120])
def test_2d_bandpath_handedness(angle):
"""Test that the x/y part is right-handed in 2D lattice.
During lattice determination, the whole 3x3 matrix is right-handed
including "dummy" z axis in 2D cells. However this did not
guarantee that the x/y part itself was right-handed, and this
test would fail for angle=60."""
cell = Cell.new([1, 1, 0, 90, 90, angle])
assert cell.get_bravais_lattice().name == 'HEX2D'
bandpath = cell.bandpath()
assert bandpath.cell.rank == 2
assert np.linalg.det(bandpath.cell[:2, :2]) > 0
def test_2d_handedness_obl():
# Previous code had a bug where left-handed cell would pick the lattice
# object corresponding to the wrong back-transformation.
dalpha = 5.1234
cell = Cell.new([2, 1, 0, 90, 90, 90 + dalpha])
lat = cell.get_bravais_lattice()
assert lat.alpha == pytest.approx(90 - dalpha)
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