LinearPCM.h

/*-------------------------------------------------------------------
Copyright 2011 Ravishankar Sundararaman, Kendra Letchworth Weaver, Deniz Gunceler

This file is part of JDFTx.

JDFTx is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

JDFTx 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with JDFTx.  If not, see <http://www.gnu.org/licenses/>.
-------------------------------------------------------------------*/

#ifndef JDFTX_ELECTRONIC_LINEARPCM_H
#define JDFTX_ELECTRONIC_LINEARPCM_H

#include <fluid/PCM.h>
#include <core/Minimize.h>

class LinearPCM : public PCM, public LinearSolvable<ScalarFieldTilde>
{
public:
        LinearPCM(const Everything& e, const FluidSolverParams& fsp); 
    virtual ~LinearPCM();
        bool prefersGummel() const { return false; }

        ScalarFieldTilde hessian(const ScalarFieldTilde&) const; 
        ScalarFieldTilde chi(const ScalarFieldTilde&) const; 
        ScalarFieldTilde precondition(const ScalarFieldTilde&) const; 

        void minimizeFluid(); 
        void loadState(const char* filename); 
        void saveState(const char* filename) const; 

protected:
        void set_internal(const ScalarFieldTilde& rhoExplicitTilde, const ScalarFieldTilde& nCavityTilde);
        double get_Adiel_and_grad_internal(ScalarFieldTilde& grad_rhoExplicitTilde, ScalarFieldTilde& grad_nCavityTilde, IonicGradient* extraForces, bool electricOnly) const;
private:
        RadialFunctionG Kkernel; ScalarField epsInv; // for preconditioner
        void updatePreconditioner(const ScalarField& epsilon, const ScalarField& kappaSq);
        
        //Optionally override epsilon and kappaSq (when used as the inner solver in NonlinearPCM's SCF):
        friend class NonlinearPCM;
        ScalarField epsilonOverride, kappaSqOverride;
        void override(const ScalarField& epsilon, const ScalarField& kappaSq);
};

#endif // JDFTX_ELECTRONIC_LINEARPCM_H