Namespace qdk::chemistry::algorithms::detail

namespace detail

Functions

std::vector<size_t> _get_inactive_space_indices(size_t nelec, const std::vector<size_t> &active_space_indices)

Helper function to determine inactive space indices for restricted orbitals.

Parameters:

  • nelec – Number of electrons

  • active_space_indices – Active space orbital indices

Returns:

Vector of inactive space orbital indices

std::pair<std::vector<size_t>, std::vector<size_t>> _get_inactive_space_indices(size_t nelec_a, size_t nelec_b, const std::vector<size_t> &active_space_indices_a, const std::vector<size_t> &active_space_indices_b)

Helper function to determine inactive space indices for unrestricted orbitals.

Parameters:

  • nelec_a – Number of alpha electrons

  • nelec_b – Number of beta electrons

  • active_space_indices_a – Alpha active space orbital indices

  • active_space_indices_b – Beta active space orbital indices

Returns:

Pair of vectors containing (alpha_inactive_space_indices, beta_inactive_space_indices)

std::tuple<double, std::vector<size_t>, Eigen::VectorXd> _sort_entropies_and_indices(std::shared_ptr<data::Wavefunction> wavefunction, bool normalize_entropies)

Helper function to sort entropies and their corresponding orbital indices in descending order.

Parameters:

  • wavefunction – The wavefunction containing orbital entropies and indices.

  • normalize_entropies – If true, normalize entropies by the maximum entropy value.

Throws:

std::runtime_error – if the wavefunction does not have single orbital entropies.

Returns:

A pair containing a vector of sorted orbital indices and a vector of sorted entropies.

std::shared_ptr<data::Orbitals> new_orbitals(std::shared_ptr<data::Wavefunction> wavefunction, const std::vector<size_t> &active_space_indices_a, const std::optional<std::vector<size_t>> &active_space_indices_b = std::nullopt)

Create a new Orbitals object with the specified active space indices.

Parameters:

  • wavefunction – The wavefunction containing the orbitals.

  • active_space_indices_a – The active space orbital indices for alpha electrons.

  • active_space_indices_b – The active space orbital indices for beta electrons (optional for restricted orbitals).

Returns:

A new Orbitals object with the specified active space indices.

std::shared_ptr<data::Wavefunction> new_wavefunction(std::shared_ptr<data::Wavefunction> wavefunction, std::shared_ptr<data::Orbitals> new_orbitals)

Create a new Wavefunction object with updated orbitals.

Generate a new Wavefunction by replacing the orbitals of the given wavefunction with the provided new orbitals, keeping the identical total, determinants.

Parameters:

  • wavefunction – The original wavefunction.

  • new_orbitals – The new orbitals to set in the wavefunction.

Returns:

A new Wavefunction object with the updated orbitals.