def test_relations(self):
n_spatial_orbitals = 2
s_plus = s_plus_operator(n_spatial_orbitals)
s_minus = s_minus_operator(n_spatial_orbitals)
sx = sx_operator(n_spatial_orbitals)
sy = sy_operator(n_spatial_orbitals)
sz = sz_operator(n_spatial_orbitals)
s_squared = s_squared_operator(n_spatial_orbitals)
identity = FermionOperator(())
self.assertEqual(normal_ordered(sx),
normal_ordered(.5 * (s_plus + s_minus)))
self.assertEqual(normal_ordered(sy),
normal_ordered((.5 / 1.j) * (s_plus - s_minus)))
self.assertEqual(normal_ordered(s_squared),
normal_ordered(sx**2 + sy**2 + sz**2))
self.assertEqual(
normal_ordered(s_squared),
normal_ordered(s_plus * s_minus + sz * (sz - identity)))
self.assertEqual(normal_ordered(commutator(s_plus, s_minus)),
normal_ordered(2 * sz))
self.assertEqual(normal_ordered(commutator(sx, sy)),
normal_ordered(1.j * sz))
def test_invalid_input(self):
with self.assertRaises(TypeError):
s_minus_operator('a')
with self.assertRaises(TypeError):
s_plus_operator('a')
with self.assertRaises(TypeError):
sx_operator('a')
with self.assertRaises(TypeError):
sy_operator('a')
with self.assertRaises(TypeError):
sz_operator('a')
with self.assertRaises(TypeError):
s_squared_operator('a')
def test_s_squared_operator(self):
op = s_squared_operator(2)
s_minus = (FermionOperator(((1, 1), (0, 0))) + FermionOperator(
((3, 1), (2, 0))))
s_plus = (FermionOperator(((0, 1), (1, 0))) + FermionOperator(
((2, 1), (3, 0))))
s_z = (FermionOperator(((0, 1), (0, 0)), 0.5) - FermionOperator(
((1, 1), (1, 0)), 0.5) + FermionOperator(
((2, 1), (2, 0)), 0.5) - FermionOperator(((3, 1), (3, 0)), 0.5))
expected = s_minus * s_plus + s_z * s_z + s_z
self.assertEqual(op, expected)
def test_uccsd_singlet_symmetries(self):
"""Test that the singlet generator has the correct symmetries."""
test_orbitals = 8
test_electrons = 4
packed_amplitude_size = uccsd_singlet_paramsize(
test_orbitals, test_electrons)
packed_amplitudes = randn(int(packed_amplitude_size))
generator = uccsd_singlet_generator(packed_amplitudes, test_orbitals,
test_electrons)
# Construct symmetry operators
sz = sz_operator(test_orbitals)
s_squared = s_squared_operator(test_orbitals)
# Check the symmetries
comm_sz = normal_ordered(commutator(generator, sz))
comm_s_squared = normal_ordered(commutator(generator, s_squared))
zero = FermionOperator()
self.assertEqual(comm_sz, zero)
self.assertEqual(comm_s_squared, zero)