def test_uccsd_singlet_get_packed_amplitudes(self): test_orbitals = 6 test_electrons = 2 sparse_single_amplitudes = numpy.zeros((test_orbitals, test_orbitals)) sparse_double_amplitudes = numpy.zeros( (test_orbitals, test_orbitals, test_orbitals, test_orbitals)) sparse_single_amplitudes[2, 0] = 0.12345 sparse_single_amplitudes[3, 1] = 0.12345 sparse_double_amplitudes[2, 0, 3, 1] = 0.9 sparse_double_amplitudes[2, 0, 4, 0] = 0.3434 sparse_double_amplitudes[5, 1, 3, 1] = 0.3434 packed_amplitudes = uccsd_singlet_get_packed_amplitudes( sparse_single_amplitudes, sparse_double_amplitudes, test_orbitals, test_electrons) self.assertEqual(len(packed_amplitudes), 5) self.assertTrue( numpy.allclose(packed_amplitudes, numpy.array([0.12345, 0., 0.9, 0., 0.3434])))
def test_ucc_h2_singlet(self): geometry = [('H', (0., 0., 0.)), ('H', (0., 0., 0.7414))] basis = 'sto-3g' multiplicity = 1 filename = os.path.join(THIS_DIRECTORY, 'data', 'H2_sto-3g_singlet_0.7414') self.molecule = MolecularData(geometry, basis, multiplicity, filename=filename) self.molecule.load() # Get molecular Hamiltonian. self.molecular_hamiltonian = self.molecule.get_molecular_hamiltonian() # Get FCI RDM. self.fci_rdm = self.molecule.get_molecular_rdm(use_fci=1) # Get explicit coefficients. self.nuclear_repulsion = self.molecular_hamiltonian.constant self.one_body = self.molecular_hamiltonian.one_body_tensor self.two_body = self.molecular_hamiltonian.two_body_tensor # Get fermion Hamiltonian. self.fermion_hamiltonian = normal_ordered( get_fermion_operator(self.molecular_hamiltonian)) # Get qubit Hamiltonian. self.qubit_hamiltonian = jordan_wigner(self.fermion_hamiltonian) # Get the sparse matrix. self.hamiltonian_matrix = get_sparse_operator( self.molecular_hamiltonian) # Test UCCSD for accuracy against FCI using loaded t amplitudes. ucc_operator = uccsd_generator(self.molecule.ccsd_single_amps, self.molecule.ccsd_double_amps) hf_state = jw_hartree_fock_state(self.molecule.n_electrons, count_qubits(self.qubit_hamiltonian)) uccsd_sparse = jordan_wigner_sparse(ucc_operator) uccsd_state = scipy.sparse.linalg.expm_multiply(uccsd_sparse, hf_state) expected_uccsd_energy = expectation(self.hamiltonian_matrix, uccsd_state) self.assertAlmostEqual(expected_uccsd_energy, self.molecule.fci_energy, places=4) print("UCCSD ENERGY: {}".format(expected_uccsd_energy)) # Test CCSD singlet for precise match against FCI using loaded t # amplitudes packed_amplitudes = uccsd_singlet_get_packed_amplitudes( self.molecule.ccsd_single_amps, self.molecule.ccsd_double_amps, self.molecule.n_qubits, self.molecule.n_electrons) ccsd_operator = uccsd_singlet_generator(packed_amplitudes, self.molecule.n_qubits, self.molecule.n_electrons, anti_hermitian=False) ccsd_sparse_r = jordan_wigner_sparse(ccsd_operator) ccsd_sparse_l = jordan_wigner_sparse( -hermitian_conjugated(ccsd_operator)) ccsd_state_r = scipy.sparse.linalg.expm_multiply( ccsd_sparse_r, hf_state) ccsd_state_l = scipy.sparse.linalg.expm_multiply( ccsd_sparse_l, hf_state) expected_ccsd_energy = ccsd_state_l.conjugate().dot( self.hamiltonian_matrix.dot(ccsd_state_r)) self.assertAlmostEqual(expected_ccsd_energy, self.molecule.fci_energy)