bond_length = 1.45
geometry = [('Li', (0., 0., 0.)), ('H', (0., 0., bond_length))]
lih_hamiltonian = openfermion.load_molecular_hamiltonian(
geometry, 'sto-3g', 1, format(bond_length), 2, 2)
@pytest.mark.parametrize(
'ansatz, trotter_algorithm, order, hamiltonian, atol', [
(SwapNetworkTrotterAnsatz(diag_coul_hamiltonian, iterations=1),
LINEAR_SWAP_NETWORK, 1, diag_coul_hamiltonian, 5e-5),
(SplitOperatorTrotterAnsatz(diag_coul_hamiltonian, iterations=1),
SPLIT_OPERATOR, 1, diag_coul_hamiltonian, 5e-5),
(LowRankTrotterAnsatz(h2_hamiltonian, iterations=1),
LOW_RANK, 0, h2_hamiltonian, 5e-5),
(LowRankTrotterAnsatz(lih_hamiltonian, iterations=1, final_rank=3),
LowRankTrotterAlgorithm(final_rank=3), 0, lih_hamiltonian, 5e-5),
(SwapNetworkTrotterHubbardAnsatz(2, 2, 1.0, 4.0, iterations=1),
LINEAR_SWAP_NETWORK, 1,
openfermion.get_diagonal_coulomb_hamiltonian(
openfermion.reorder(
openfermion.fermi_hubbard(2, 2, 1.0, 4.0),
openfermion.up_then_down)
),
5e-5)
])
def test_trotter_ansatzes_default_initial_params_iterations_1(
ansatz, trotter_algorithm, order, hamiltonian, atol):
"""Check that a Trotter ansatz with one iteration and default parameters
is consistent with time evolution with one Trotter step."""
objective = HamiltonianObjective(hamiltonian)
(diag_coul_hamiltonian, long_time, diag_coul_initial_state,
diag_coul_exact_state, 0, 6, SPLIT_OPERATOR, .999),
(diag_coul_hamiltonian, long_time, diag_coul_initial_state,
diag_coul_exact_state, 1, 1, SPLIT_OPERATOR, .99),
(diag_coul_hamiltonian, long_time, diag_coul_initial_state,
diag_coul_exact_state, 2, 1, SPLIT_OPERATOR, .99999),
(hubbard_hamiltonian, long_time, hubbard_initial_state,
hubbard_exact_state, 0, 3, SPLIT_OPERATOR, .999),
(hubbard_hamiltonian, long_time, hubbard_initial_state,
hubbard_exact_state, 0, 6, SPLIT_OPERATOR, .9999),
(h2_hamiltonian, longer_time, h2_initial_state, h2_exact_state, 0, 1,
LOW_RANK, .99),
(h2_hamiltonian, longer_time, h2_initial_state, h2_exact_state, 0, 10,
LOW_RANK, .9999),
(lih_hamiltonian, longer_time, lih_initial_state, lih_exact_state, 0,
1, LowRankTrotterAlgorithm(final_rank=2), .999),
(lih_hamiltonian, longer_time, lih_initial_state, lih_exact_state, 0,
10, LowRankTrotterAlgorithm(final_rank=2), .9999),
])
def test_simulate_trotter_simulate(hamiltonian, time, initial_state,
exact_state, order, n_steps, algorithm,
result_fidelity):
n_qubits = openfermion.count_qubits(hamiltonian)
qubits = cirq.LineQubit.range(n_qubits)
start_state = initial_state
circuit = cirq.Circuit(
simulate_trotter(qubits, hamiltonian, time, n_steps, order, algorithm))