RPASusceptibility.h

/* Copyright 2017 Kristofer Björnson
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef COM_DAFER45_TBTK_RPA_SUSCEPTIBILITY_CALCULATOR
#define COM_DAFER45_TBTK_RPA_SUSCEPTIBILITY_CALCULATOR

#include "TBTK/InteractionAmplitude.h"
#include "TBTK/Property/Susceptibility.h"
#include "TBTK/MomentumSpaceContext.h"
#include "TBTK/SerializableVector.h"
#include "TBTK/Solver/Solver.h"

#include <complex>

namespace TBTK{
namespace Solver{

class RPASusceptibility : public Solver, public Communicator{
public:
    RPASusceptibility(
        const MomentumSpaceContext &momentumSpaceContext,
        const Property::Susceptibility &susceptibility
    );

    const Property::Susceptibility& getBareSusceptibility() const;

    RPASusceptibility* createSlave();

    void setInteractionAmplitudes(
        const std::vector<InteractionAmplitude> &interactionAmplitudes
    );

    virtual std::vector<std::complex<double>> calculateSusceptibility(
        const Index &index,
        const std::vector<std::complex<double>> &energies
    );

    IndexedDataTree<
        std::vector<std::complex<double>>
    > calculateRPASusceptibility(
        const Index &index
    );
private:
    const Property::Susceptibility &bareSusceptibility;

    std::vector<InteractionAmplitude> interactionAmplitudes;

    const MomentumSpaceContext &momentumSpaceContext;

    void invertMatrix(
        std::complex<double> *matrix,
        unsigned int dimensions
    );

    std::vector<std::vector<std::vector<
        std::vector<std::vector<std::complex<double>>>
    >>> rpaSusceptibilityMainAlgorithm(
        const Index &index,
        const std::vector<InteractionAmplitude> &interactionAmpltiudes
    );
};

inline const Property::Susceptibility&
RPASusceptibility::getBareSusceptibility() const{
    return bareSusceptibility;
}

inline void RPASusceptibility::setInteractionAmplitudes(
    const std::vector<InteractionAmplitude> &interactionAmplitudes
){
    this->interactionAmplitudes = interactionAmplitudes;
}

inline std::vector<std::complex<double>>
RPASusceptibility::calculateSusceptibility(
    const Index &index,
    const std::vector<std::complex<double>> &energies
){
    TBTKExit(
        "Solver::RPSSusceptibility::calculateSusceptibility()",
        "This function is not supported by this Solver.",
        ""
    );
}

};  //End of namespace Solver
};  //End of namespace TBTK

#endif