ERNewtonLocalizer.hpp

Go to the documentation of this file.

// This file is part of GQCG-GQCP.
//
// Copyright (C) 2017-2020  the GQCG developers
//
// GQCG-GQCP is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GQCG-GQCP is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with GQCG-GQCP.  If not, see <http://www.gnu.org/licenses/>.
 
#pragma once
 
 
#include "Basis/SpinorBasis/OrbitalSpace.hpp"
#include "QCMethod/OrbitalOptimization/NewtonOrbitalOptimizer.hpp"
 
 
namespace GQCP {
 
 
class ERNewtonLocalizer: public NewtonOrbitalOptimizer {
private:
    OrbitalSpace orbital_space;  // the occupied-virtual orbital space
 
 
public:
    // CONSTRUCTORS
 
    ERNewtonLocalizer(const OrbitalSpace orbital_space, std::shared_ptr<BaseHessianModifier> hessian_modifier, const double convergence_threshold = 1.0e-08, const size_t maximum_number_of_iterations = 128);
 
 
    // PUBLIC OVERRIDDEN METHODS
 
    SquareMatrix<double> calculateGradientMatrix(const RSQHamiltonian<double>& sq_hamiltonian) const override;
 
    SquareRankFourTensor<double> calculateHessianTensor(const RSQHamiltonian<double>& sq_hamiltonian) const override;
 
    ROrbitalRotationGenerators<double> calculateNewFullOrbitalGenerators(const RSQHamiltonian<double>& sq_hamiltonian) const override;
 
    void prepareOrbitalDerivativesCalculation(const RSQHamiltonian<double>& sq_hamiltonian) override {}
 
 
    // PUBLIC METHODS
 
    double calculateGradientMatrixElement(const RSQHamiltonian<double>& sq_hamiltonian, const size_t i, const size_t j) const;
 
    double calculateHessianTensorElement(const RSQHamiltonian<double>& sq_hamiltonian, const size_t i, const size_t j, const size_t k, const size_t l) const;
};
 
 
}  // namespace GQCP