openfermion.hamiltonians.HartreeFockFunctional

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Implementation of the objective function code for Restricted Hartree-Fock

View aliases

Main aliases

openfermion.HartreeFockFunctional, openfermion.hamiltonians.hartree_fock.HartreeFockFunctional

openfermion.hamiltonians.HartreeFockFunctional(
    *,
    one_body_integrals: np.ndarray,
    two_body_integrals: np.ndarray,
    overlap: np.ndarray,
    n_electrons: int,
    model='rhf',
    nuclear_repulsion: Optional[float] = 0.0,
    initial_orbitals: Optional[Union[None, Callable]] = None
)

The object transforms a variety of input types into the appropriate output. It does this by analyzing the type and size of the input based on its knowledge of each type.

Args
one_body_integrals	integrals in the atomic orbital basis for the one-body potential.
two_body_integrals	integrals in the atomic obrital basis for the two-body potential ordered according to phi{p}(r1)^{*}phi{q}^{*}(r2) x phi{r}(r2)phi{s}(r1)
overlap	overlap integrals in the atomic orbital basis
n_electrons	number of electrons total
model	Optional flag for performing restricted-, unrestricted-, or generalized- hartree-fock.
nuclear_repulsion	Optional nuclear repulsion term. Energy is shifted by this amount. default is 0.
initial_orbitals	Method for producing the initial orbitals from the atomic orbitals. Default is defining the core orbitals.

Methods

energy_from_rhf_opdm

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energy_from_rhf_opdm(
    opdm_aa: np.ndarray
) -> float

Compute the energy given a spin-up opdm

Args
opdm_aa	spin-up opdm. Should be an n x n matrix where n is the number of spatial orbitals

Returns: RHF energy

rdms_from_rhf_opdm

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rdms_from_rhf_opdm(
    opdm_aa: np.ndarray
) -> openfermion.ops.InteractionRDM

Generate spin-orbital InteractionRDM object from the alpha-spin opdm.

Args
opdm_aa	single spin sector of the 1-particle denstiy matrix

Returns: InteractionRDM object for full spin-orbital 1-RDM and 2-RDM

rhf_global_gradient

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rhf_global_gradient(
    params: np.ndarray, alpha_opdm: np.ndarray
)

Compute rhf global gradient

Args
params	rhf-parameters for rotation matrix.
alpha_opdm	1-RDM corresponding to results of basis rotation parameterized by `params'.

Returns: gradient vector the same size as the input `params'