VanDerWaals.h

/*-------------------------------------------------------------------
Copyright 2012 Deniz Gunceler, Kendra Letchworth Weaver

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_VANDERWAALS_H
#define JDFTX_ELECTRONIC_VANDERWAALS_H

#include <electronic/RadialFunction.h>
#include <electronic/common.h>
#include <core/ScalarFieldArray.h>
#include <core/Coulomb.h>

class VanDerWaals
{
public:
        VanDerWaals(const Everything &everything);
        ~VanDerWaals();
        
        const static int unitParticle = -1; 
        
        double energyAndGrad(std::vector<Atom>& atoms, const double scaleFac) const;
        
        double energyAndGrad(const std::vector< std::vector< vector3<> > >& atpos, const ScalarFieldTildeArray& Ntilde, const std::vector<int>& atomicNumber,
                const double scaleFac, ScalarFieldTildeArray* grad_Ntilde=0, IonicGradient* forces=0) const;
        
        double getScaleFactor(string exCorrName, double scaleOverride=0.) const;
        
        struct AtomParams
        {       double C6;
                double R0;
                AtomParams(double SI_C6=0., double SI_R0=0.);
        };
        AtomParams getParams(int atomicNumber, int sp) const; 
        
private:
        const Everything* e;
        
        std::vector<AtomParams> atomParams; 
        std::map<string,double> scalingFactor; 
        
        const RadialFunctionG& getRadialFunction(int Z1, int Z2, int sp1, int sp2) const;
        
        std::map<std::pair<int,int>,RadialFunctionG> radialFunctions;
};

#endif // JDFTX_ELECTRONIC_VANDERWAALS_H