Problem.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 PROBLEM_CHEMPS2_H
#define PROBLEM_CHEMPS2_H

#include "Hamiltonian.h"

namespace CheMPS2{
   class Problem{

      public:
      

         Problem(const Hamiltonian * Hamin, const int TwoSin, const int Nin, const int Irrepin);
         
         virtual ~Problem();
         

         int gL() const{ return L; }
         

         int gSy() const{ return Ham->getNGroup(); }
         

         int gIrrep(const int nOrb) const;
         

         int gTwoS() const{ return TwoS; }
         

         int gN() const{ return N; }
         

         int gIrrep() const{ return Irrep; }
         

         double gEconst() const{ return Ham->getEconst(); }
         

         double gMxElement(const int alpha, const int beta, const int gamma, const int delta) const;
         

         void setMxElement(const int alpha, const int beta, const int gamma, const int delta, const double value);
         
         void construct_mxelem();
         

         bool checkConsistency() const;
         

         bool gReorder() const;
         

         int gf1(const int HamOrb) const;
         

         int gf2(const int DMRGOrb) const;
         
         void SetupReorderD2h();
         
         void SetupReorderC2v();
         

         void setup_reorder_custom(int * dmrg2ham);
         

         void setup_reorder_dinfh(int * docc, const double sp_threshold=1e-5);
         
      private:
      
         //Pointer to the Hamiltonian --> constructed and destructed outside of this class
         const Hamiltonian * Ham;
         
         //The number of orbitals
         int L;
         
         //Twice the targeted spin
         int TwoS;
         
         //The targeted particle number
         int N;
         
         //The targeted irrep
         int Irrep;
         
         //Whether or not to reorder
         bool bReorder;
         
         //f1[HamiltonianIndex] = DMRGindex
         int * f1;
         
         //f2[DMRGIndex] = HamiltonianIndex
         int * f2;
         
         //Matrix element table
         double * mx_elem;
         
   };
}

#endif