source: ThirdParty/mpqc_open/src/lib/chemistry/qc/cints/overlap.cc@ e9f307

//
// overlap.cc
//
// Copyright (C) 2001 Edward Valeev
//
// Author: Edward Valeev <edward.valeev@chemistry.gatech.edu>
// Maintainer: EV
//
// This file is part of the SC Toolkit.
//
// The SC Toolkit is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// The SC Toolkit 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 Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
// the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
//
// The U.S. Government is granted a limited license as per AL 91-7.
//

#ifdef __GNUG__
#pragma implementation
#endif

#include <util/misc/math.h>

#include <chemistry/qc/cints/int1e.h>
#include <chemistry/qc/cints/macros.h>

using namespace sc;

void Int1eCints::overlap(int sh1, int sh2)
{
  zero_buffers_();
  compute_doublet_info_(sh1, sh2);

  int maxam1 = int_shell1_->max_am();
  int minam1 = int_shell1_->min_am();
  int maxam2 = int_shell2_->max_am();
  int minam2 = int_shell2_->min_am();
  
  if (maxam1 != minam1 || maxam2 != minam2) {
    overlap_full_general_();
  }
  else {
    overlap_full_general_();
  }
}


void Int1eCints::overlap_full_general_()
{
  int maxam1 = int_shell1_->max_am();
  int maxam2 = int_shell2_->max_am();

  /* See if need to transform to spherical harmonics */
  bool need_cart2sph_transform = false;
  if (int_shell1_->has_pure() ||
      int_shell2_->has_pure())
    need_cart2sph_transform = true;

  /* See if contraction quartets need to be resorted into a shell quartet */
  bool need_sort_to_shell_doublet = false;
  int num_gen_shells = 0;
  if (int_shell1_->ncontraction() > 1)
    num_gen_shells++;
  if (int_shell2_->ncontraction() > 1)
    num_gen_shells++;
  if (maxam1 + maxam2 && num_gen_shells >= 1)
    need_sort_to_shell_doublet = true;

  /* Determine where integrals need to go at each stage */
  if (need_sort_to_shell_doublet) {
      prim_ints_ = cart_ints_;
      if (need_cart2sph_transform)
        contr_doublets_ = sphharm_ints_;
      else
        contr_doublets_ = cart_ints_;
      shell_doublet_ = target_ints_buffer_;
    }
    else {
      if (need_cart2sph_transform) {
        prim_ints_ = cart_ints_;
        contr_doublets_ = target_ints_buffer_;
        shell_doublet_ = target_ints_buffer_;
      }
      else {
        prim_ints_ = target_ints_buffer_;
        shell_doublet_ = target_ints_buffer_;
      }
    }

  /* Begin loops over primitives. */
  for (int p1=0; p1<int_shell1_->nprimitive(); p1++) {
    double a1 = int_shell1_->exponent(p1);
    for (int p2=0; p2<int_shell2_->nprimitive(); p2++) {
      double a2 = int_shell2_->exponent(p2);
      
      double gamma = a1+a2;
      double oog = 1.0/gamma;
      double over_pf = exp(-a1*a2*doublet_info_.AB2*oog)*sqrt(M_PI*oog)*M_PI*oog;
      
      double P[3], PA[3], PB[3], PC[3];
      for(int xyz=0; xyz<3; xyz++) {
        P[xyz] = (a1*doublet_info_.A[xyz] + a2*doublet_info_.B[xyz])*oog;
        PA[xyz] = P[xyz] - doublet_info_.A[xyz];
        PB[xyz] = P[xyz] - doublet_info_.B[xyz];
      }

      OI_OSrecurs_(OIX_,OIY_,OIZ_,PA,PB,gamma,maxam1,maxam2);

      /*--- contract each buffer into appropriate location ---*/
      double *ints_buf = prim_ints_;
      for (int gc1=0; gc1<int_shell1_->ncontraction(); gc1++) {
        double norm1 = int_shell1_->coefficient_unnorm(gc1,p1);
        int am1 = int_shell1_->am(gc1);
        for (int gc2=0; gc2<int_shell2_->ncontraction(); gc2++) {
          double norm2 = int_shell2_->coefficient_unnorm(gc2,p2);
          int am2 = int_shell2_->am(gc2);
          double total_pf = over_pf * norm1 * norm2;
          
          int k1,l1,m1,k2,l2,m2;
          FOR_CART(k1,l1,m1,am1)
            FOR_CART(k2,l2,m2,am2)
              *(ints_buf++) += OIX_[k1][k2] * OIY_[l1][l2] * OIZ_[m1][m2] * total_pf;
            END_FOR_CART
          END_FOR_CART
          
        }
      }
    }
  }

  if (need_cart2sph_transform)
    transform_contrquartets_(prim_ints_,contr_doublets_);

  if (need_sort_to_shell_doublet)
    sort_contrdoublets_to_shelldoublet_(contr_doublets_,shell_doublet_);
}


void Int1eCints::overlap_sameam_general_()
{
  int tam1 = int_shell1_->am(0);
  int tam2 = int_shell2_->am(0);

  /* Begin loops over primitives. */
  for (int p1=0; p1<int_shell1_->nprimitive(); p1++) {
    double a1 = int_shell1_->exponent(p1);
    for (int p2=0; p2<int_shell2_->nprimitive(); p2++) {
      double a2 = int_shell2_->exponent(p2);
      
      double gamma = a1+a2;
      double oog = 1.0/gamma;
      double over_pf = exp(-a1*a2*doublet_info_.AB2*oog)*sqrt(M_PI*oog)*M_PI*oog;
      
      double P[3], PA[3], PB[3], PC[3];
      for(int xyz=0; xyz<3; xyz++) {
        P[xyz] = (a1*doublet_info_.A[xyz] + a2*doublet_info_.B[xyz])*oog;
        PA[xyz] = P[xyz] - doublet_info_.A[xyz];
        PB[xyz] = P[xyz] - doublet_info_.B[xyz];
      }

      OI_OSrecurs_(OIX_,OIY_,OIZ_,PA,PB,gamma,tam1,tam2);

      /*--- contract each buffer into appropriate location ---*/
      double *ints_buf = cart_ints_;
      for (int gc1=0; gc1<int_shell1_->ncontraction(); gc1++) {
        double norm1 = int_shell1_->coefficient_unnorm(gc1,p1);
        for (int gc2=0; gc2<int_shell2_->ncontraction(); gc2++) {
          double norm2 = int_shell2_->coefficient_unnorm(gc2,p2);
          double total_pf = over_pf * norm1 * norm2;
          
          int k1,l1,m1,k2,l2,m2;
          FOR_CART(k1,l1,m1,tam1)
            FOR_CART(k2,l2,m2,tam2)
              *(ints_buf++) += OIX_[k1][k2] * OIY_[l1][l2] * OIZ_[m1][m2] * total_pf;
            END_FOR_CART
          END_FOR_CART
          
        }
      }
    }
  }

  /*----------------------------------------------------------------------
    transform to spherical harmonics and/or resort to the target ordering
   ----------------------------------------------------------------------*/
  
  /*--- sort to the target ordering ---*/
  double *source_ints_buf = cart_ints_;
  double *target_ints_buf = target_ints_buffer_;
  int target_bf1_offset = 0;
  int target_bf2_offset = 0;
  int nbf2 = int_shell2_->nfunction();
  for (int gc1=0; gc1<int_shell1_->ncontraction(); gc1++) {
    int tsize1 = INT_NCART_NN(tam1);
    for (int gc2=0; gc2<int_shell2_->ncontraction(); gc2++) {
      int tsize2 = INT_NCART_NN(tam2);
      
      int k1,l1,m1,k2,l2,m2;
      int bf1 = 0;
      FOR_CART(k1,l1,m1,tam1)
        double *target_ints_buf = target_ints_buffer_ + (target_bf1_offset+bf1)*nbf2 +
                                  target_bf2_offset;
        FOR_CART(k2,l2,m2,tam2)
          *(target_ints_buf++) = *(source_ints_buf++);
        END_FOR_CART
        bf1++;
      END_FOR_CART
      target_bf2_offset += tsize2;
    }
    target_bf1_offset += tsize1;
  }
}


/////////////////////////////////////////////////////////////////////////////

// Local Variables:
// mode: c++
// c-file-style: "CLJ"
// End: