def test_bit_to_fermion_creation_order(self):
"""Return the representation of a bitstring as FermionOperators acting
on the vacuum.
"""
bit = (1 << 6) + 31
self.assertEqual(openfermion_utils.bit_to_fermion_creation(bit),
FermionOperator('0^ 1^ 2^ 3^ 4^ 6^', 1.0))
def test_bit_to_fermion_creation_beta(self):
"""Spin index conversetion between the fqe and opernfermion is that
beta/down fermions are indicated by index*2+1. bit 1 is index 1 for
down spin.
"""
self.assertEqual(openfermion_utils.bit_to_fermion_creation(1, 'down'),
FermionOperator('1^', 1.0))
def test_bit_to_fermion_creation_alpha(self):
"""Spin index conversetion between the fqe and opernfermion is that
alpha/up fermions are indicated by index*2. bit 1 is index 0 for up
spin.
"""
self.assertEqual(openfermion_utils.bit_to_fermion_creation(1, 'up'),
FermionOperator('0^', 1.0))
def test_bit_to_fermion_creation_null(self):
"""Empty bitstrings will return None.
"""
self.assertIsNone(openfermion_utils.bit_to_fermion_creation(0))
def test_bit_to_fermion_creation_spinless(self):
"""Spinless particles are converted directly into their occupation index.
"""
self.assertEqual(openfermion_utils.bit_to_fermion_creation(1),
FermionOperator('0^', 1.0))