JacobiOrbitalOptimizer.hpp

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// 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/Transformations/JacobiRotation.hpp"
#include "QCMethod/OrbitalOptimization/BaseOrbitalOptimizer.hpp"
 
 
namespace GQCP {
 
 
class JacobiOrbitalOptimizer: public BaseOrbitalOptimizer {
protected:
    size_t dim;  // the dimension of the orbital space that should be scanned. The valid orbital indices then are 0 ... dim (not included)
 
    using pair_type = std::pair<JacobiRotation, double>;
    pair_type optimal_jacobi_with_scalar;  // holds the optimal Jacobi parameters and the corresponding value for the scalar function trying to optimize
 
 
public:
    // CONSTRUCTORS
 
    JacobiOrbitalOptimizer(const size_t dim, const double convergence_threshold = 1.0e-08, const size_t maximum_number_of_iterations = 128);
 
 
    // DESTRUCTOR
 
    virtual ~JacobiOrbitalOptimizer() = default;
 
 
    // PUBLIC PURE VIRTUAL METHODS
 
    virtual void calculateJacobiCoefficients(const RSQHamiltonian<double>& sq_hamiltonian, const size_t p, const size_t q) = 0;
 
    virtual double calculateOptimalRotationAngle(const RSQHamiltonian<double>& sq_hamiltonian, const size_t p, const size_t q) const = 0;
 
    virtual double calculateScalarFunctionChange(const RSQHamiltonian<double>& sq_hamiltonian, const JacobiRotation& jacobi_rot_par) const = 0;
 
    virtual void prepareJacobiSpecificConvergenceChecking(const RSQHamiltonian<double>& sq_hamiltonian) = 0;
 
 
    // PUBLIC OVERRIDDEN METHODS
 
    RTransformation<double> calculateNewRotationMatrix(const RSQHamiltonian<double>& sq_hamiltonian) const override;
 
    bool checkForConvergence(const RSQHamiltonian<double>& sq_hamiltonian) const override;
 
    void prepareConvergenceChecking(const RSQHamiltonian<double>& sq_hamiltonian) override;
 
 
    // PUBLIC METHODS
 
    std::pair<JacobiRotation, double> calculateOptimalJacobiParameters(const RSQHamiltonian<double>& sq_hamiltonian);
 
    std::function<bool(const pair_type&, const pair_type&)> comparer() const;
};
 
 
}  // namespace GQCP