Hamiltonian.h

/*
   CheMPS2: a spin-adapted implementation of DMRG for ab initio quantum chemistry
   Copyright (C) 2013-2016 Sebastian Wouters

   This program 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 2 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#ifndef HAMILTONIAN_CHEMPS2_H
#define HAMILTONIAN_CHEMPS2_H

#include <string>

#include "Irreps.h"
#include "TwoIndex.h"
#include "FourIndex.h"
#include "Options.h"

using std::string;

namespace CheMPS2{
   class Hamiltonian{

      public:
      

         Hamiltonian(const int Norbitals, const int nGroup, const int * OrbIrreps);
         

         Hamiltonian(const string filename, const int psi4groupnumber);
         

         Hamiltonian(const bool fileh5, const string main_file=HAMILTONIAN_ParentStorageName, const string file_tmat=HAMILTONIAN_TmatStorageName, const string file_vmat=HAMILTONIAN_VmatStorageName);
         
         virtual ~Hamiltonian();
         

         int getL() const;


         int getNGroup() const;


         int getOrbitalIrrep(const int nOrb) const;
         

         void setEconst(const double val);
         

         void setTmat(const int index1, const int index2, const double val);
         

         void setVmat(const int index1, const int index2, const int index3, const int index4, const double val);
         

         void addToVmat(const int index1, const int index2, const int index3, const int index4, const double val);
         

         double getEconst() const;
         

         double getTmat(const int index1, const int index2) const;
         

         double getVmat(const int index1, const int index2, const int index3, const int index4) const;
         

         const TwoIndex * getTmat();
         

         FourIndex * getVmat();
         

         void save(const string file_parent=HAMILTONIAN_ParentStorageName, const string file_tmat=HAMILTONIAN_TmatStorageName, const string file_vmat=HAMILTONIAN_VmatStorageName) const;
         

         void read(const string file_parent=HAMILTONIAN_ParentStorageName, const string file_tmat=HAMILTONIAN_TmatStorageName, const string file_vmat=HAMILTONIAN_VmatStorageName);
         

         void writeFCIDUMP( const string fcidumpfile, const int Nelec, const int TwoS, const int TargetIrrep ) const;
         
         void debugcheck() const;


         void readfock( const string fockfile, double * fockmx, const bool printinfo ) const;

      private:
      
         //number of orbitals
         int L;
         
         //symmetry info
         Irreps SymmInfo;
         
         //irrep of each orbital
         int * orb2irrep;
         
         //number of orbitals per irrep
         int * irrep2num_orb;
         
         //index of an orbital within irrep block
         int * orb2indexSy;
         
         //1-particle matrix elements
         TwoIndex * Tmat;
         
         //2-particle matrix elements
         FourIndex * Vmat;
         
         //Constant part of the Hamiltonian
         double Econst;
         
         //If filename=="LOADH5" in Hamiltonian::Hamiltonian then the HDF5 Hamiltonian is loaded
         void CreateAndFillFromH5(const string file_parent, const string file_tmat, const string file_vmat);
         
         //Load the FCIDUMP Hamiltonian (with molpro irreps!)
         void CreateAndFillFromFCIDUMP( const string fcidumpfile );
         
   };
}

#endif