Update test_molecule.py

tests for driver.hamiltonian

tests/test_molecule.py

@@ -6,8 +6,11 @@
 import numpy as np
 import pytest
 from qibo import gates, models
+from qibo.hamiltonians import SymbolicHamiltonian
+from qibo.symbols import X, Y, Z
 
 from qibochem.driver.molecule import Molecule
+from qibochem.driver import hamiltonian
 from qibochem.measurement.expectation import expectation
 
 
@@ -38,6 +41,68 @@ def test_run_pyscf_molecule_xyz():
     assert lih.e_hf == pytest.approx(lih_ref_energy)
 
 
+def test_fermionic_hamiltonian():
+
+    h2 = Molecule([("H", (0.0, 0.0, 0.0)), ("H", (0.0, 0.0, 0.7))])
+    h2.run_pyscf()
+    h2_ferm_ham = hamiltonian.fermionic_hamiltonian(h2.oei, h2.tei, h2.e_nuc)
+
+    # a^\dagger_0 a_0
+    ref_one_body_tensor = np.array([[-1.27785301,  0.,          0.,          0.        ],
+                                    [ 0.,         -1.27785301,  0.,          0.        ],
+                                    [ 0.,          0.,         -0.4482997,   0.        ],
+                                    [ 0.,          0.,          0.,         -0.4482997 ]])
+
+    assert np.isclose(h2_ferm_ham[()], 0.7559674441714287)
+    assert np.allclose(h2_ferm_ham.one_body_tensor, ref_one_body_tensor)
+
+def test_parse_pauli_string_1():
+
+    pauli_string = ((0, 'X'), (1, 'Y'))
+    qibo_pauli_string = hamiltonian.parse_pauli_string(pauli_string, 0.5)
+    ref_pauli_string = '0.5*X0*Y1'
+    assert str(qibo_pauli_string) == ref_pauli_string
+
+def test_parse_pauli_string_2():
+
+    qibo_pauli_string = hamiltonian.parse_pauli_string(None, 0.1)
+    assert str(qibo_pauli_string) == '0.1'
+
+def test_qubit_hamiltonian():
+
+    h2 = Molecule([("H", (0.0, 0.0, 0.0)), ("H", (0.0, 0.0, 0.7))])
+    h2.run_pyscf()
+    h2_ferm_ham = hamiltonian.fermionic_hamiltonian(h2.oei, h2.tei, h2.e_nuc)
+    h2_qubit_ham_jw = hamiltonian.qubit_hamiltonian(h2_ferm_ham, "jw")
+    h2_qubit_ham_bk = hamiltonian.qubit_hamiltonian(h2_ferm_ham, "bk")
+    ref_h2_qubit_ham_jw = {(): -0.04207897647782238, ((0, 'Z'),): 0.17771287465139918, ((1, 'Z'),): 0.1777128746513992, ((2, 'Z'),): -0.24274280513140478, ((3, 'Z'),): -0.24274280513140478, ((0, 'Z'), (1, 'Z')): 0.17059738328801052, ((0, 'Z'), (2, 'Z')): 0.12293305056183809, ((0, 'Z'), (3, 'Z')): 0.16768319457718972, ((1, 'Z'), (2, 'Z')): 0.16768319457718972, ((1, 'Z'), (3, 'Z')): 0.12293305056183809, ((2, 'Z'), (3, 'Z')): 0.17627640804319608, ((0, 'X'), (1, 'X'), (2, 'Y'), (3, 'Y')): -0.04475014401535165, ((0, 'X'), (1, 'Y'), (2, 'Y'), (3, 'X')): 0.04475014401535165, ((0, 'Y'), (1, 'X'), (2, 'X'), (3, 'Y')): 0.04475014401535165, ((0, 'Y'), (1, 'Y'), (2, 'X'), (3, 'X')): -0.04475014401535165}
+    ref_h2_qubit_ham_bk = {((0, 'Z'),): 0.17771287465139923, (): -0.04207897647782244, ((0, 'Z'), (1, 'Z')): 0.17771287465139918, ((2, 'Z'),): -0.24274280513140484, ((1, 'Z'), (2, 'Z'), (3, 'Z')): -0.24274280513140484, ((0, 'Y'), (1, 'Z'), (2, 'Y')): 0.04475014401535165, ((0, 'X'), (1, 'Z'), (2, 'X')): 0.04475014401535165, ((0, 'X'), (1, 'Z'), (2, 'X'), (3, 'Z')): 0.04475014401535165, ((0, 'Y'), (1, 'Z'), (2, 'Y'), (3, 'Z')): 0.04475014401535165, ((1, 'Z'),): 0.17059738328801052, ((0, 'Z'), (2, 'Z')): 0.12293305056183809, ((0, 'Z'), (1, 'Z'), (2, 'Z')): 0.16768319457718972, ((0, 'Z'), (1, 'Z'), (2, 'Z'), (3, 'Z')): 0.16768319457718972, ((0, 'Z'), (2, 'Z'), (3, 'Z')): 0.12293305056183809, ((1, 'Z'), (3, 'Z')): 0.17627640804319608}
+
+    keylist_jw = h2_qubit_ham_jw.terms.keys()
+    keylist_bk = h2_qubit_ham_bk.terms.keys()
+    jw_array = np.array([h2_qubit_ham_jw.terms[key] for key in keylist_jw])    
+    bk_array = np.array([h2_qubit_ham_bk.terms[key] for key in keylist_bk])    
+
+    keylist_ref_jw = ref_h2_qubit_ham_jw.keys()
+    keylist_ref_bk = ref_h2_qubit_ham_bk.keys()
+    ref_jw_array = np.array([ref_h2_qubit_ham_jw[key] for key in keylist_ref_jw])
+    ref_bk_array = np.array([ref_h2_qubit_ham_bk[key] for key in keylist_ref_bk])
+
+    assert np.allclose(jw_array, ref_jw_array)
+    assert np.allclose(bk_array, ref_bk_array)
+
+
+def test_symbolic_hamiltonian():
+    h2 = Molecule([("H", (0.0, 0.0, 0.0)), ("H", (0.0, 0.0, 0.7))])
+    h2.run_pyscf()
+    h2_ferm_ham = hamiltonian.fermionic_hamiltonian(h2.oei, h2.tei, h2.e_nuc)
+    h2_qubit_ham = hamiltonian.qubit_hamiltonian(h2_ferm_ham, "jw")
+    h2_sym_ham = hamiltonian.symbolic_hamiltonian(h2_qubit_ham)
+    ref_ham = -0.0420789764778224 - 0.0447501440153516*X(0)*X(1)*Y(2)*Y(3) + 0.0447501440153516*X(0)*Y(1)*Y(2)*X(3) + 0.0447501440153516*Y(0)*X(1)*X(2)*Y(3) - 0.0447501440153516*Y(0)*Y(1)*X(2)*X(3) + 0.177712874651399*Z(0) + 0.170597383288011*Z(0)*Z(1) + 0.122933050561838*Z(0)*Z(2) + 0.16768319457719*Z(0)*Z(3) + 0.177712874651399*Z(1) + 0.16768319457719*Z(1)*Z(2) + 0.122933050561838*Z(1)*Z(3) - 0.242742805131405*Z(2) + 0.176276408043196*Z(2)*Z(3) - 0.242742805131405*Z(3)
+    ref_sym_ham = SymbolicHamiltonian(ref_ham)
+
+    assert np.allclose(h2_sym_ham.matrix, ref_sym_ham.matrix)
+
 @pytest.mark.skip(reason="psi4 doesn't offer pip install, so needs to be installed through conda or manually.")
 def test_run_psi4():
     """PSI4 driver"""