def begin_iterations(self, orbital_energies, orbital_coefficients):
previous_total_energy = 0
while True:
density_matrix = density_matrix_restricted(orbital_coefficients,
self.electrons)
core_matrix, elst_matrix, xc_matrix \
= self.hamiltonian_matrix_factory.create(density_matrix)
ks_matrix = core_matrix + elst_matrix + xc_matrix
total_energy = self.calculate.restricted(orbital_energies,
density_matrix,
elst_matrix, xc_matrix)
delta_energy = previous_total_energy - total_energy
previous_total_energy = total_energy
print('SCF ENERGY: ' + str(total_energy) + ' a.u.')
if abs(delta_energy) < self.threshold:
break
ks_matrix = self.diis.fock_matrix(ks_matrix, density_matrix)
orbital_energies, orbital_coefficients \
= self.linear_algebra.diagonalize(ks_matrix)
return total_energy, orbital_energies, orbital_coefficients
def test_method_calculate_returns_density_matrix_element_for_1_1(self):
element = density_matrix_restricted(self.orbital_coefficients,
2).item(1, 1)
testing.assert_approx_equal(element, 0.0391, 3)
def test_method_calculate_returns_density_matrix_element_for_0_0(self):
element = density_matrix_restricted(self.orbital_coefficients,
2).item(0, 0)
testing.assert_approx_equal(element, 1.7266, 4)