def calculate(self, i, j):
s_ij = 0
if i == j:
return 1
else:
primitives_i = self.basis_set_array[i].primitive_gaussian_array
primitives_j = self.basis_set_array[j].primitive_gaussian_array
for primitive_a, primitive_b in itertools.product(primitives_i, primitives_j):
c_1 = primitive_a.contraction
c_2 = primitive_b.contraction
n_1 = primitive_a.normalisation
n_2 = primitive_b.normalisation
s_ij += n_1 * n_2 * c_1 * c_2 * orbital_overlap(primitive_a, primitive_b)
return s_ij
def calculate(self, i, j):
t_ij = 0
primitives_i = self.basis_set_array[i].primitive_gaussian_array
primitives_j = self.basis_set_array[j].primitive_gaussian_array
for primitive_a, primitive_b in itertools.product(primitives_i, primitives_j):
c_1 = primitive_a.contraction
c_2 = primitive_b.contraction
n_1 = primitive_a.normalisation
n_2 = primitive_b.normalisation
primitives_k = del_operator(primitive_b)
s_ij = 0
for primitive_c in primitives_k:
c_3 = primitive_c.contraction
s_ij += n_1 * n_2 * c_1 * c_2 * c_3 * orbital_overlap(primitive_a, primitive_c)
t_ij += s_ij
return t_ij
