minihf.hamiltonian.integral.electron_repulsion module

class minihf.hamiltonian.integral.electron_repulsion.ElectronRepulsion

Bases: object

The Obara-Saika scheme for three-dimensional nuclear attraction integral over primitive Gaussian orbitals.

__init__(self)

Initialize the instance.

contracted(self, cga, cgb, cgc, cgd)

Evaluate integral over contracted GTOs.

target(self, N, pga, pgb, pgc, pgd)

Obtain the target integral in the Obara-Saika recurrence relations.

recurrence(self, r, N, pga, pgb, pgc, pgd, pga_1, pga_2, pgb_1, pgc_1, pgd_1)

Run the recurrence.

new_gaussian(self, r, pga, pgb, pgc, pgd)

Generate all the new primitive GTOs in the Obara-Saika recurrence relations.

contracted(cga, cgb, cgc, cgd)

Evaluate integral over contracted GTOs.

Parameters:

• cga (ContractedGaussian) – The first contracted gaussian orbital.

• cgb (ContractedGaussian) – The second contracted gaussian orbital.

• cgc (ContractedGaussian) – The third contracted gaussian orbital.

• cgd (ContractedGaussian) – The fourth contracted gaussian orbital.

Returns:

result – Integral value.

Return type:

float

target(N, pga, pgb, pgc, pgd)

Obtain the target integral in the Obara-Saika recurrence relations.

recurrence(r, N, pga, pgb, pgc, pgd, pga_1, pga_2, pgb_1, pgc_1, pgd_1)

Run the recurrence.

new_gaussian(r, pga, pgb, pgc, pgd)

Generate all the new primitive GTOs in the Obara-Saika recurrence relations.

Parameters:

• r (int) – Cartesian index 0, 1, 2.

• N (int) – Order of the boys function F_{N}(x).

• pga (PrimitiveGaussian) – The first primitive gaussian orbital.

• pgb (PrimitiveGaussian) – The second primitive gaussian orbital.

• pgc (PrimitiveGaussian) – The third primitive gaussian orbital.

• pgd (PrimitiveGaussian) – The fourth primitive gaussian orbital.

Returns:

result – Tuple of 5 PrimitiveGaussian orbital instance.

Return type:

Tuple(pg,pg,pg,pg,pg)