ffsim.NumNumAnsatzOpSpinBalanced¶

class ffsim.NumNumAnsatzOpSpinBalanced(norb, interaction_pairs, thetas)[source]¶

A number-number interaction ansatz operator.

The number-number interaction ansatz consists of a sequence of number-number interactions.

Attributes

`norb`	The number of spatial orbitals.
`interaction_pairs`	The orbital pairs to apply the number-number interactions to.
`thetas`	The angles for the number-number interactions.

interaction_pairs: tuple[list[tuple[int, int]], list[tuple[int, int]]]¶: The orbital pairs to apply the number-number interactions to.

thetas: tuple[ndarray, ndarray]¶: The angles for the number-number interactions.

Methods

`from_diag_coulomb_mats`(diag_coulomb_mats)	Initialize the operator from a diagonal Coulomb matrix.
`from_parameters`(params, norb, interaction_pairs)	Initialize the operator from a real-valued parameter vector.
`n_params`(interaction_pairs)	Return the number of parameters of an ansatz with given settings.
`to_diag_coulomb_mats`()	Convert the operator to diagonal Coulomb matrices.
`to_parameters`()	Convert the operator to a real-valued parameter vector.

static from_diag_coulomb_mats(diag_coulomb_mats)[source]¶

Initialize the operator from a diagonal Coulomb matrix.

Parameters:: diag_coulomb_mats (tuple[ndarray, ndarray] | ndarray) – The diagonal Coulomb matrices. Should be a pair of matrices, with the first matrix representing same-spin interactions and the second matrix representing different-spin interactions.
Return type:: NumNumAnsatzOpSpinBalanced

static from_parameters(params, norb, interaction_pairs)[source]¶

Initialize the operator from a real-valued parameter vector.

Parameters:

params (ndarray) – The real-valued parameter vector.
norb (int) – The number of spatial orbitals.
interaction_pairs (tuple[list[tuple[int, int]], list[tuple[int, int]]]) – The orbital pairs to apply the number-number interactions to.

Return type:

NumNumAnsatzOpSpinBalanced

static n_params(interaction_pairs)[source]¶

Return the number of parameters of an ansatz with given settings.

Parameters:: interaction_pairs (tuple[list[tuple[int, int]], list[tuple[int, int]]]) – The orbital pairs to apply the number-number interactions to.
Return type:: int

to_diag_coulomb_mats()[source]¶

Convert the operator to diagonal Coulomb matrices.

Return type:: ndarray
Returns:: A Numpy array of shape (2, norb, norb) holding two matrices. The first matrix holds the same-spin interactions and the second matrix holds the different-spin interactions.

to_parameters()[source]¶

Convert the operator to a real-valued parameter vector.