def test_distance_fractional(self):
""" Test the fractional distance between atoms """
atm1 = Atom("He", [0, 0, 0])
atm2 = Atom("He", [1, 0, 0])
self.assertEqual(distance_fractional(atm1, atm2), 1)
self.assertEqual(distance_fractional(atm1, atm2),
distance_fractional(atm2, atm1))
def test_atomic_distance_different_lattice():
"""Test that fractional and cartesian distances
between atoms in different lattices raises an error."""
lattice1 = Lattice(np.eye(3))
lattice2 = Lattice(2 * np.eye(3))
atm1 = Atom("He", [0, 0, 0], lattice=lattice1)
atm2 = Atom("He", [1, 0, 0], lattice=lattice2)
with pytest.raises(RuntimeError):
distance_fractional(atm1, atm2)
with pytest.raises(RuntimeError):
distance_cartesian(atm1, atm2)
def test_distance_different_lattice(self):
""" Test that fractional and cartesian distances
between atoms in different lattices raises an error. """
lattice1 = Lattice(np.eye(3))
lattice2 = Lattice(2 * np.eye(3))
atm1 = Atom("He", [0, 0, 0], lattice=lattice1)
atm2 = Atom("He", [1, 0, 0], lattice=lattice2)
with self.subTest("Fractional distance"):
with self.assertRaises(RuntimeError):
distance_fractional(atm1, atm2)
with self.subTest("Cartesian distance"):
with self.assertRaises(RuntimeError):
distance_cartesian(atm1, atm2)
def test_atomic_distance_fractional():
"""Test the fractional distance between atoms"""
atm1 = Atom("He", [0, 0, 0])
atm2 = Atom("He", [1, 0, 0])
assert distance_fractional(atm1, atm2) == 1
assert distance_fractional(atm1, atm2) == distance_fractional(atm2, atm1)