fqe.restricted_hamiltonian.RestrictedHamiltonian

The Restricted Hamiltonian is characterized by having identical alpha

Inherits From: Hamiltonian

fqe.restricted_hamiltonian.RestrictedHamiltonian(
    tensors: Tuple[np.ndarray, ...],
    e_0: complex = (0.0 + 0.0j)
) -> None

and beta terms and no alpha/beta mixing blocks. An example is non-relativistic molecular Hamiltonians in the RHF basis

tensors Variable length tuple containg between one and four numpy.arrays of increasing rank. The tensors contain the n-body hamiltonian elements. Tensors up to the highest order must be included even if the lower terms are full of zeros.
e_0 Scalar potential associated with the Hamiltonian.

Methods

calc_diag_transform

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calc_diag_transform() -> np.ndarray

Performs a unitary digaonlizing transformation of the one-body term and returns that transformation.

conserve_number

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conserve_number() -> bool

Returns True if the Hamiltonian is number conserving, else False.

diag_values

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diag_values() -> np.ndarray

Returns the diagonal values packed into a single dimension.

diagonal

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diagonal() -> bool

Returns True if the Hamiltonian is diagonal, else False.

diagonal_coulomb

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diagonal_coulomb() -> bool

Returns True if the Hamiltonian is diagonal coloumb, else False.

dim

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dim() -> int

Returns the orbital dimension of the Hamiltonian arrays.

e_0

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e_0()

Returns the scalar potential of the Hamiltonian.

iht

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iht(
    time: float
) -> Tuple[np.ndarray, ...]

Return the matrices of the Hamiltonian prepared for time evolution.

Args
time The time step.

quadratic

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quadratic() -> bool

Returns True if the Hamiltonian is quadratic, else False.

rank

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rank()

Returns the rank of the largest tensor.

tensor

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tensor(
    rank: int
) -> np.ndarray

Returns a single nbody tensor based on its rank.

Args
rank Indexes the single nbody tensor to return.

tensors

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tensors() -> Tuple[np.ndarray, ...]

Returns all tensors in order of their rank.

transform

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transform(
    trans: np.ndarray
) -> np.ndarray

Tranform the one body term using the provided matrix.

Args
trans Unitary transformation.

Returns
Transformed one-body Hamiltonian as a numpy.ndarray.