ffsim.multireference_state_prod¶
- ffsim.multireference_state_prod(hamiltonian, ansatz_operator, reference_occupations, norb, nelec, root=0, tol=1e-08)[source]¶
Compute multireference state for a product ansatz operator.
- Parameters:
hamiltonian (
MolecularHamiltonian|SingleFactorizedHamiltonian) – The Hamiltonian.ansatz_operator (
tuple[SupportsApplyUnitary,SupportsApplyUnitary]) – The alpha and beta parts of the ansatz operator.reference_occupations (
Sequence[tuple[Sequence[int],Sequence[int]]]) – The orbital occupations of the reference states.norb (
int) – The number of spatial orbitals.nelec (
tuple[int,int]) – The number of alpha and beta electrons.root (
int) – The index of the desired eigenvector. Defaults to 0, which yields the lowest-energy state.tol (
float) – Numerical tolerance to use for the single factorization of the molecular Hamiltonian. If the input is already a SingleFactorizedHamiltonian, this argument is ignored.
- Return type:
- Returns:
The energy of the multireference state, and the state itself.