openqemist.electronic_structure_solvers.fci_solver package¶

openqemist.electronic_structure_solvers.fci_solver.fci_solver module¶

Perform Full CI calculation.

The electronic structure calculation employing the full configuration interaction (CI) method is done here.

class openqemist.electronic_structure_solvers.fci_solver.fci_solver.FCISolver[source]

Perform Full CI calculation.

Uses the Full CI method to solve the electronic structure problem. PySCF program will be utilized. Users can also provide a function that takes a pyscf.gto.Mole as its first argument and pyscf.scf.RHF as its second.

cisolver

The Full CI object.

Type

pyscf.fci.direct_spin0.FCI

ci

The CI wavefunction (float64).

Type

numpy.array

norb

The number of molecular orbitals.

Type

int

nelec

The number of electrons.

Type

int

get_rdm()[source]

Calculate the 1- and 2-particle RDMs.

Calculate the Full CI reduced density matrices.

Returns

One & two-particle RDMs (fci_onerdm & fci_twordm, float64).

Return type

(numpy.array, numpy.array)

Raises

RuntimeError – If no simulation has been run.

simulate(molecule, mean_field=None)[source]

Perform the simulation (energy calculation) for the molecule.

If the mean field is not provided it is automatically calculated. pyscf.ao2mo is used to transform the AO integrals into MO integrals.

Parameters
• molecule (pyscf.gto.Mole) – The molecule to simulate.

• mean_field (pyscf.scf.RHF) – The mean field of the molecule.

Returns

The Full CI energy (energy).

Return type

float64