File DensityMatrixBuilder.h¶

Copyright

This code is licensed under the 3-clause BSD license.

Copyright ETH Zurich, Laboratory for Physical Chemistry, Reiher Group.

See LICENSE.txt for details.

namespace Scine

This header file contains functions that allow for common notation for common things that can be done at a different degree of derivatives.

This header contains alias definitions defining which classes to use for the different degrees of derivatives.

namespace Utils

namespace LcaoUtil

class DensityMatrixBuilder

#include <DensityMatrixBuilder.h>

Class to generate density matrices from coefficient matrices. Different possibilities to do so:

Specify the number of electrons
Specify which orbitals to consider
Specify the number of electrons and some number of swaps TODO: Use the class MolecularOrbitalsManipulation instead of reimplementing the mixes and swaps

Public Types

using PartlyOccupiedOrbital = std::pair<int, double>: Alias for partly occupied orbital, given by orbital index and its occupation [0-1] (UHF) vs [0-2] (RHF).

Public Functions

DensityMatrix generateRestrictedForNumberElectrons(int nElectrons) const: Generates a restricted density matrix for the given number of electrons.

DensityMatrix generateUnrestrictedForNumberElectronsAndMultiplicity(int nElectrons, int spinMultiplicity) const: Generates an unrestricted density matrix for the given number of electrons and corresponding spin multiplicity.

DensityMatrix generateUnrestrictedForNumberAlphaAndBetaElectrons(int nAlpha, int nBeta) const: Generates an unrestricted density matrix for the given number of alpha and beta electrons.

DensityMatrix generateRestrictedForSpecifiedOrbitals(const std::vector<int> &doublyOccupiedOrbitals) const: Generates a restricted density matrix from specified molecular orbitals (eigenvectors), which will be doubly filled.

DensityMatrix generateUnrestrictedForSpecifiedOrbitals(const std::vector<int> &alphaOrbitals, const std::vector<int> &betaOrbitals) const: Generates an unrestricted density matrix from specified molecular orbitals (eigenvectors).

DensityMatrix generateRestrictedWithSwaps(const std::vector<MolecularOrbitalsManipulation::DeprecatedSwap> &swaps, int nElectrons) const

Generates a restricted density matrix with given Swaps.

DensityMatrix generateUnrestrictedWithSwaps(const std::vector<MolecularOrbitalsManipulation::DeprecatedSwap> &alphaSwaps, const std::vector<MolecularOrbitalsManipulation::DeprecatedSwap> &betaSwaps, int nAlpha, int nBeta) const: Generates an unrestricted density matrix with given Swaps.

DensityMatrix generateRestrictedForSpecifiedPartlyOccupiedOrbitals(const std::vector<PartlyOccupiedOrbital> &orbitals): Generates a restricted density matrix from specified molecular orbitals (eigenvectors) and their occupation [0-2].

DensityMatrix generateUnrestrictedForSpecifiedPartlyOccupiedOrbitals(const std::vector<PartlyOccupiedOrbital> &alphaOrbitals, const std::vector<PartlyOccupiedOrbital> &betaOrbitals): Generates an unrestricted density matrix from specified molecular orbitals (eigenvectors) and their occupation [0-1].

DensityMatrix generateRestrictedWithMixing(const std::vector<MolecularOrbitalsManipulation::DeprecatedMix> &mix, int nElectrons) const

Generates a restricted density matrix with given Mixing.

DensityMatrix generateUnrestrictedWithMixing(const std::vector<MolecularOrbitalsManipulation::DeprecatedMix> &alphaMix, const std::vector<MolecularOrbitalsManipulation::DeprecatedMix> &betaMix, int nAlpha, int nBeta) const: Generates an unrestricted density matrix with given Mixing.

Private Functions

Eigen::MatrixXd calculateSingleOrbitalDensity(const Eigen::VectorXd &eigenvector) const¶

Eigen::MatrixXd calculateBlockOrbitalDensity(const Eigen::MatrixXd &eigenvectors) const¶

Eigen::MatrixXd calculateDensityMatrix(const Eigen::MatrixXd &coefficientMatrix, int nOccupiedLevels) const¶

Eigen::MatrixXd calculateDifferenceSwapDensity(const Eigen::MatrixXd &coefficientMatrix, const std::vector<MolecularOrbitalsManipulation::DeprecatedSwap> &swaps, int homoIndex) const¶

Eigen::MatrixXd calculateDifferenceMixDensity(const Eigen::MatrixXd &coefficientMatrix, const std::vector<MolecularOrbitalsManipulation::DeprecatedMix> &mix, int homoIndex) const¶

Private Members