def testDerivH2(self):
"""
Test Derivatives of dihydrogen
"""
# build integrator object
integrator = PyQInt()
# build hydrogen molecule
mol = Molecule('H2')
mol.add_atom('H', -0.5, 0.0, 0.0)
mol.add_atom('H', 0.5, 0.0, 0.0)
cgfs, nuclei = mol.build_basis('sto3g')
# calculate derivative towards H1 in the x-direction
fx1 = integrator.repulsion_deriv(cgfs[0], cgfs[0], cgfs[0], cgfs[0],
nuclei[0][0], 0)
fx2 = integrator.repulsion_deriv(cgfs[1], cgfs[1], cgfs[1], cgfs[1],
nuclei[0][0], 0)
# mol | nuc_id | cgf_id1 | cgf_id2 | cgf_id3 | cgf_id4 | coord
ans1 = calculate_force_finite_difference(mol, 0, 0, 0, 0, 0, 0)
ans2 = calculate_force_finite_difference(mol, 0, 1, 1, 1, 1, 0)
# assert that the repulsion of two CGFs that spawn from
# the same nucleus will not change in energy due to a
# change of the nucleus coordinates
np.testing.assert_almost_equal(fx1, ans1, 4)
np.testing.assert_almost_equal(fx1, 0.0, 4)
np.testing.assert_almost_equal(fx2, ans2, 4)
np.testing.assert_almost_equal(fx2, 0.0, 4)
# assert that the cross-terms will change
fx3 = integrator.repulsion_deriv(cgfs[0], cgfs[0], cgfs[1], cgfs[1],
nuclei[0][0], 0)
fx4 = integrator.repulsion_deriv(cgfs[0], cgfs[0], cgfs[1], cgfs[1],
nuclei[1][0], 0)
fx5 = integrator.repulsion_deriv(cgfs[1], cgfs[0], cgfs[1], cgfs[0],
nuclei[0][0], 0)
fx6 = integrator.repulsion_deriv(cgfs[1], cgfs[0], cgfs[1], cgfs[0],
nuclei[1][0], 0)
# mol | nuc_id | cgf_id1 | cgf_id2 | cgf_id3 | cgf_id4 | coord
ans3 = calculate_force_finite_difference(mol, 0, 0, 0, 1, 1, 0)
ans4 = calculate_force_finite_difference(mol, 1, 0, 0, 1, 1, 0)
ans5 = calculate_force_finite_difference(mol, 0, 1, 0, 1, 0, 0)
ans6 = calculate_force_finite_difference(mol, 1, 1, 0, 1, 0, 0)
np.testing.assert_almost_equal(fx3, ans3, 4)
np.testing.assert_almost_equal(fx4, ans4, 4)
np.testing.assert_almost_equal(fx5, ans5, 4)
np.testing.assert_almost_equal(fx6, ans6, 4)
def testDerivH2O(self):
"""
Test Derivatives of water
"""
# build integrator object
integrator = PyQInt()
# build hydrogen molecule
mol = Molecule()
mol.add_atom('O', 0.0, 0.0, 0.0)
mol.add_atom('H', 0.7570, 0.5860, 0.0)
mol.add_atom('H', -0.7570, 0.5860, 0.0)
cgfs, nuclei = mol.build_basis('sto3g')
# calculate derivative of 2s AO on oxygen towards H1 in the x-direction
fx1 = integrator.repulsion_deriv(cgfs[2], cgfs[2], cgfs[2], cgfs[2],
nuclei[1][0], 0) # px
fx2 = integrator.repulsion_deriv(cgfs[2], cgfs[3], cgfs[3], cgfs[3],
nuclei[1][0], 0) # py
ans1 = calculate_force_finite_difference(mol, 1, 2, 2, 2, 2, 0)
ans2 = calculate_force_finite_difference(mol, 1, 3, 3, 3, 3, 0)
# assert that the repulsion of two CGFs that spawn from
# the same nucleus will not change in energy due to a
# change of the nucleus coordinates
np.testing.assert_almost_equal(fx1, ans1, 4)
np.testing.assert_almost_equal(fx2, ans2, 4)
# assert that the cross-terms will change
fx3 = integrator.repulsion_deriv(cgfs[3], cgfs[3], cgfs[5], cgfs[5],
nuclei[0][0], 0)
fx4 = integrator.repulsion_deriv(cgfs[3], cgfs[3], cgfs[5], cgfs[5],
nuclei[1][0], 0)
fx5 = integrator.repulsion_deriv(cgfs[5], cgfs[3], cgfs[5], cgfs[3],
nuclei[0][0], 0)
fx6 = integrator.repulsion_deriv(cgfs[3], cgfs[5], cgfs[3], cgfs[5],
nuclei[1][0], 0)
# mol | nuc_id | cgf_id1 | cgf_id2 | cgf_id3 | cgf_id4 | coord
ans3 = calculate_force_finite_difference(mol, 0, 3, 3, 5, 5, 0)
ans4 = calculate_force_finite_difference(mol, 1, 3, 3, 5, 5, 0)
ans5 = calculate_force_finite_difference(mol, 0, 5, 3, 5, 3, 0)
ans6 = calculate_force_finite_difference(mol, 1, 3, 5, 3, 5, 0)
# assert that these are non-trivial tests
self.assertFalse(ans3 == 0.0)
self.assertFalse(ans4 == 0.0)
self.assertFalse(ans5 == 0.0)
self.assertFalse(ans6 == 0.0)
np.testing.assert_almost_equal(fx3, ans3, 10)
np.testing.assert_almost_equal(fx4, ans4, 10)
np.testing.assert_almost_equal(fx5, ans5, 10)
np.testing.assert_almost_equal(fx6, ans6, 10)
# assert that the cross-terms will change
fx7 = integrator.repulsion_deriv(cgfs[2], cgfs[3], cgfs[5], cgfs[6],
nuclei[0][0], 0)
fx8 = integrator.repulsion_deriv(cgfs[2], cgfs[3], cgfs[5], cgfs[6],
nuclei[1][0], 1)
fx9 = integrator.repulsion_deriv(cgfs[2], cgfs[3], cgfs[5], cgfs[6],
nuclei[2][0], 1)
# get answers
ans7 = calculate_force_finite_difference(mol, 0, 2, 3, 5, 6, 0)
ans8 = calculate_force_finite_difference(mol, 1, 2, 3, 5, 6, 1)
ans9 = calculate_force_finite_difference(mol, 2, 2, 3, 5, 6, 1)
# assert that these are non-trivial tests
self.assertFalse(ans7 == 0.0)
self.assertFalse(ans8 == 0.0)
self.assertFalse(ans9 == 0.0)
np.testing.assert_almost_equal(fx7, ans7, 10)
np.testing.assert_almost_equal(fx8, ans8, 10)
np.testing.assert_almost_equal(fx9, ans9, 10)