Accelerated s2

src/Determinants/diagonalize_CI.irp.f

@@ -48,7 +48,7 @@ END_PROVIDER
    integer                        :: i_other_state
    double precision, allocatable  :: eigenvectors(:,:), eigenvalues(:)
    integer                        :: i_state
-   double precision               :: s2,e_0
+   double precision               :: e_0
    integer                        :: i,j,k
    double precision, allocatable  :: s2_eigvalues(:)
    double precision, allocatable  :: e_array(:)
@@ -71,9 +71,9 @@ END_PROVIDER
      
      call davidson_diag(psi_det,CI_eigenvectors,CI_electronic_energy,&
          size(CI_eigenvectors,1),N_det,N_states_diag,N_int,output_determinants)
-     do j=1,N_states_diag
+
-       call get_s2_u0(psi_det,CI_eigenvectors(1,j),N_det,size(CI_eigenvectors,1),CI_eigenvectors_s2(j))
+     call get_s2_u0_nstates(CI_eigenvectors_s2,CI_eigenvectors,N_det,psi_det,N_int,&
-     enddo
+         N_states_diag,size(CI_eigenvectors,1))
      
      
    else if (diag_algorithm == "Lapack") then
@@ -88,11 +88,11 @@ END_PROVIDER
        allocate (s2_eigvalues(N_det))
        allocate(index_good_state_array(N_det),good_state_array(N_det))
        good_state_array = .False.
+       call get_s2_u0_nstates(s2_eigvalues,eigenvectors,N_det,psi_det,N_int,&
+         N_det,size(eigenvectors,1))
        do j=1,N_det
-         call get_s2_u0(psi_det,eigenvectors(1,j),N_det,size(eigenvectors,1),s2)
-         s2_eigvalues(j) = s2
          ! Select at least n_states states with S^2 values closed to "expected_s2"
-         if(dabs(s2-expected_s2).le.0.5d0)then
+         if(dabs(s2_eigvalues(j)-expected_s2).le.0.5d0)then
            i_state +=1
            index_good_state_array(i_state) = j
            good_state_array(j) = .True.
@@ -117,12 +117,11 @@ END_PROVIDER
            if(i_state+i_other_state.gt.n_states_diag)then
              exit
            endif
-           call get_s2_u0(psi_det,eigenvectors(1,j),N_det,size(eigenvectors,1),s2)
            do i=1,N_det
              CI_eigenvectors(i,i_state+i_other_state) = eigenvectors(i,j)
            enddo
            CI_electronic_energy(i_state+i_other_state) = eigenvalues(j)
-           CI_eigenvectors_s2(i_state+i_other_state) = s2
+           CI_eigenvectors_s2(i_state+i_other_state) = s2_eigvalues(i_state+i_other_state)
          enddo
          
        else
@@ -146,14 +145,14 @@ END_PROVIDER
        deallocate(index_good_state_array,good_state_array)
        deallocate(s2_eigvalues)
      else
+       call get_s2_u0_nstates(CI_eigenvectors_s2,eigenvectors,N_det,psi_det,N_int,&
+          min(N_det,N_states_diag),size(eigenvectors,1))
        ! Select the "N_states_diag" states of lowest energy
        do j=1,min(N_det,N_states_diag)
-         call get_s2_u0(psi_det,eigenvectors(1,j),N_det,N_det,s2)
          do i=1,N_det
            CI_eigenvectors(i,j) = eigenvectors(i,j)
          enddo
          CI_electronic_energy(j) = eigenvalues(j)
-         CI_eigenvectors_s2(j) = s2
        enddo
      endif
      deallocate(eigenvectors,eigenvalues)
@@ -162,7 +161,7 @@ END_PROVIDER
 
    if( s2_eig.and.(n_states_diag > 1).and.(n_det >= n_states_diag) )then
       ! Diagonalizing S^2 within the "n_states_diag" states found
-      allocate(s2_eigvalues(N_states_diag))
+      allocate(s2_eigvalues(N_states_diag), e_array(N_states_diag))
       call diagonalize_s2_betweenstates(psi_det,CI_eigenvectors,n_det,size(psi_det,3),size(CI_eigenvectors,1),min(n_states_diag,n_det),s2_eigvalues)
       
       do j = 1, N_states_diag
@@ -170,6 +169,7 @@ END_PROVIDER
           psi_coef(i,j) = CI_eigenvectors(i,j)
         enddo
       enddo
+      call u0_H_u_0_nstates(e_array,psi_coef,n_det,psi_det,N_int,N_states_diag,psi_det_size)
      
       ! Browsing the "n_states_diag" states and getting the lowest in energy "n_states" ones that have the S^2 value
       ! closer to the "expected_s2" set as input
@@ -185,15 +185,13 @@ END_PROVIDER
         endif
       enddo
       ! Sorting the i_state good states by energy
-      allocate(e_array(i_state),iorder(i_state))
+      allocate(iorder(i_state))
       do j = 1, i_state
         do i = 1, N_det
           CI_eigenvectors(i,j) = psi_coef(i,index_good_state_array(j))
         enddo
         CI_eigenvectors_s2(j) = s2_eigvalues(index_good_state_array(j))
-        call u0_H_u_0(e_0,CI_eigenvectors(1,j),n_det,psi_det,N_int)
+        CI_electronic_energy(j) = e_array(j)
-        CI_electronic_energy(j) = e_0
-        e_array(j) = e_0
         iorder(j) = j
       enddo
       call dsort(e_array,iorder,i_state)
@@ -203,14 +201,7 @@ END_PROVIDER
         do i = 1, N_det
           CI_eigenvectors(i,j) = psi_coef(i,index_good_state_array(iorder(j)))
         enddo
-        !    call u0_H_u_0(e_0,CI_eigenvectors(1,j),n_det,psi_det,N_int)
-        !    print*,'e    = ',CI_electronic_energy(j)
-        !    print*,'<e>  = ',e_0
-        !    call get_s2_u0(psi_det,CI_eigenvectors(1,j),N_det,size(CI_eigenvectors,1),s2)
-        !    print*,'s^2  = ',CI_eigenvectors_s2(j)
-        !    print*,'<s^2>= ',s2
       enddo
-      deallocate(e_array,iorder)
       
       ! Then setting the other states without any specific energy order
       i_other_state = 0
@@ -221,10 +212,9 @@ END_PROVIDER
           CI_eigenvectors(i,i_state + i_other_state) = psi_coef(i,j)
         enddo
         CI_eigenvectors_s2(i_state + i_other_state) = s2_eigvalues(j)
-        call u0_H_u_0(e_0,CI_eigenvectors(1,i_state + i_other_state),n_det,psi_det,N_int)
+        CI_electronic_energy(i_state + i_other_state) = e_array(i_state + i_other_state)
-        CI_electronic_energy(i_state + i_other_state) = e_0
       enddo
-      deallocate(index_good_state_array,good_state_array)
+      deallocate(iorder,e_array,index_good_state_array,good_state_array)
        
      deallocate(s2_eigvalues)
      

src/Determinants/s2.irp.f

@@ -69,41 +69,11 @@ BEGIN_PROVIDER [ double precision, s2_values, (N_states) ]
 ! array of the averaged values of the S^2 operator on the various states
  END_DOC
  integer :: i
- double precision :: s2
+ call get_s2_u0_nstates(s2_values,psi_coef,n_det,psi_det,N_int,N_states,psi_det_size)
- do i = 1, N_states
-  call get_s2_u0(psi_det,psi_coef(1,i),n_det,size(psi_coef,1),s2)
-  s2_values(i) = s2
- enddo
 
 END_PROVIDER
 
 
-subroutine get_s2_u0_old(psi_keys_tmp,psi_coefs_tmp,n,nmax,s2)
- implicit none
- use bitmasks
- integer, intent(in) :: n,nmax
- integer(bit_kind), intent(in) :: psi_keys_tmp(N_int,2,nmax)
- double precision, intent(in) :: psi_coefs_tmp(nmax)
- double precision, intent(out) :: s2
- integer :: i,j,l
- double precision :: s2_tmp
- s2 = 0.d0
- !$OMP PARALLEL DO DEFAULT(NONE) &
- !$OMP PRIVATE(i,j,s2_tmp) SHARED(n,psi_coefs_tmp,psi_keys_tmp,N_int) REDUCTION(+:s2) SCHEDULE(dynamic) 
- do i=1,n
-   do j=i+1,n
-     call get_s2(psi_keys_tmp(1,1,i),psi_keys_tmp(1,1,j),s2_tmp,N_int)
-     s2 += psi_coefs_tmp(i)*psi_coefs_tmp(j)*s2_tmp
-   enddo
- enddo
- !$OMP END PARALLEL DO
- s2 = s2+s2
- do i=1,n
-   call get_s2(psi_keys_tmp(1,1,i),psi_keys_tmp(1,1,i),s2_tmp,N_int)
-   s2 += psi_coefs_tmp(i)*psi_coefs_tmp(i)*s2_tmp
- enddo
- s2 +=  S_z2_Sz
-end
 
 subroutine get_s2_u0(psi_keys_tmp,psi_coefs_tmp,n,nmax,s2)
   implicit none
@@ -112,6 +82,148 @@ subroutine get_s2_u0(psi_keys_tmp,psi_coefs_tmp,n,nmax,s2)
   integer(bit_kind), intent(in)  :: psi_keys_tmp(N_int,2,nmax)
   double precision, intent(in)   :: psi_coefs_tmp(nmax)
   double precision, intent(out)  :: s2
+  call get_s2_u0_nstates(s2,psi_coefs_tmp,n,psi_keys_tmp,N_int,1,nmax)
+end
+
+
+subroutine get_s2_u0_nstates(s2,u_0,n,keys_tmp,Nint,N_st,sze_8)
+  use bitmasks
+  implicit none
+  BEGIN_DOC
+  ! Computes s2  = <u_0|S^2|u_0>
+  !
+  ! n : number of determinants
+  !
+  END_DOC
+  integer, intent(in)            :: N_st,n,Nint, sze_8
+  double precision, intent(out)  :: s2(N_st)
+  double precision, intent(in)   :: u_0(sze_8,N_st)
+  integer(bit_kind),intent(in)   :: keys_tmp(Nint,2,n)
+  double precision               :: s2_tmp
+  double precision               :: s2t(N_st)
+  integer                        :: i,j,k,l, jj,ii
+  integer                        :: i0, j0
+  
+  integer, allocatable           :: shortcut(:,:), sort_idx(:,:)
+  integer(bit_kind), allocatable :: sorted(:,:,:), version(:,:,:)
+  integer(bit_kind)              :: sorted_i(Nint)
+  
+  integer                        :: sh, sh2, ni, exa, ext, org_i, org_j, endi, istate
+  
+
+  ASSERT (Nint > 0)
+  ASSERT (Nint == N_int)
+  ASSERT (n>0)
+  PROVIDE ref_bitmask_energy davidson_criterion
+
+  allocate (shortcut(0:n+1,2), sort_idx(n,2), sorted(Nint,n,2), version(Nint,n,2))
+  s2 = 0.d0
+
+  call sort_dets_ab_v(keys_tmp, sorted(1,1,1), sort_idx(1,1), shortcut(0,1), version(1,1,1), n, Nint)
+  call sort_dets_ba_v(keys_tmp, sorted(1,1,2), sort_idx(1,2), shortcut(0,2), version(1,1,2), n, Nint)
+  
+  !$OMP PARALLEL DEFAULT(NONE)                                       &
+      !$OMP PRIVATE(i,s2_tmp,j,k,jj,s2t,ii,sh,sh2,ni,exa,ext,org_i,org_j,endi,sorted_i,istate)&
+      !$OMP SHARED(n,u_0,keys_tmp,Nint,s2,sorted,shortcut,sort_idx,version,N_st,sze_8)
+  s2t = 0.d0
+  
+  !$OMP DO SCHEDULE(dynamic)
+  do sh=1,shortcut(0,1)
+    do sh2=sh,shortcut(0,1)
+      exa = 0
+      do ni=1,Nint
+        exa = exa + popcnt(xor(version(ni,sh,1), version(ni,sh2,1)))
+      end do
+      if(exa > 2) then
+        cycle
+      end if
+      
+      do i=shortcut(sh,1),shortcut(sh+1,1)-1
+        org_i = sort_idx(i,1)
+        if(sh==sh2) then
+          endi = i-1
+        else
+          endi = shortcut(sh2+1,1)-1
+        end if
+        do ni=1,Nint
+          sorted_i(ni) = sorted(ni,i,1)
+        enddo
+        
+        do j=shortcut(sh2,1),endi
+          org_j = sort_idx(j,1)
+          ext = exa
+          do ni=1,Nint
+            ext = ext + popcnt(xor(sorted_i(ni), sorted(ni,j,1)))
+          end do
+          if(ext <= 4) then
+            call get_s2(keys_tmp(1,1,org_i),keys_tmp(1,1,org_j),s2_tmp,Nint)
+            do istate=1,N_st
+              s2t(istate)  = s2t(istate) + u_0(org_i,istate)*u_0(org_j,istate)*s2_tmp
+            enddo
+          endif
+        enddo
+      enddo
+    enddo
+  enddo
+  !$OMP END DO NOWAIT
+  
+  !$OMP DO SCHEDULE(dynamic)
+  do sh=1,shortcut(0,2)
+    do i=shortcut(sh,2),shortcut(sh+1,2)-1
+      org_i = sort_idx(i,2)
+      do j=shortcut(sh,2),i-1
+        org_j = sort_idx(j,2)
+        ext = 0
+        do ni=1,Nint
+          ext = ext + popcnt(xor(sorted(ni,i,2), sorted(ni,j,2)))
+        end do
+        if(ext == 4) then
+          call get_s2(keys_tmp(1,1,org_i),keys_tmp(1,1,org_j),s2_tmp,Nint)
+          do istate=1,N_st
+            s2t(istate)  = s2t(istate) + u_0(org_i,istate)*u_0(org_j,istate)*s2_tmp
+          enddo
+        end if
+      end do
+    end do
+  enddo
+  !$OMP END DO NOWAIT
+  
+  !$OMP CRITICAL
+  do istate=1,N_st
+      s2(istate) = s2(istate) + 2.d0*s2t(istate)
+  enddo
+  !$OMP END CRITICAL
+
+  !$OMP END PARALLEL
+  
+  do i=1,n
+    call get_s2(keys_tmp(1,1,i),keys_tmp(1,1,i),s2_tmp,Nint)
+    do istate=1,N_st
+      s2(istate) = s2(istate) + u_0(i,istate)*u_0(i,istate)*s2_tmp
+    enddo
+  enddo
+  do istate=1,N_st
+      s2(istate) += S_z2_Sz
+  enddo
+  deallocate (shortcut, sort_idx, sorted, version)
+end
+
+
+
+
+
+
+
+
+
+
+subroutine get_s2_u0_nstates_old(psi_keys_tmp,psi_coefs_tmp,n,nmax,s2,N_st)
+  implicit none
+  use bitmasks
+  integer, intent(in)            :: n,nmax, N_st
+  integer(bit_kind), intent(in)  :: psi_keys_tmp(N_int,2,nmax)
+  double precision, intent(in)   :: psi_coefs_tmp(nmax)
+  double precision, intent(out)  :: s2
   double precision               :: s2_tmp
   integer                        :: i,j,l,jj,ii
   integer, allocatable           :: idx(:)
@@ -119,13 +231,12 @@ subroutine get_s2_u0(psi_keys_tmp,psi_coefs_tmp,n,nmax,s2)
   integer, allocatable           :: shortcut(:), sort_idx(:)
   integer(bit_kind), allocatable :: sorted(:,:), version(:,:)
   integer                        :: sh, sh2, ni, exa, ext, org_i, org_j, endi, pass
-  double precision               :: davidson_threshold_bis
   
   allocate (shortcut(0:n+1), sort_idx(n), sorted(N_int,n), version(N_int,n))
   s2 = 0.d0
-  davidson_threshold_bis = threshold_davidson
   call sort_dets_ab_v(psi_keys_tmp, sorted, sort_idx, shortcut, version, n, N_int)
   
+  PROVIDE threshold_davidson
   !$OMP PARALLEL DEFAULT(NONE)                                       &
       !$OMP PRIVATE(i,j,s2_tmp,sh, sh2, ni, exa, ext, org_i, org_j, endi, pass)&
       !$OMP SHARED(n,psi_coefs_tmp,psi_keys_tmp,N_int,threshold_davidson,shortcut,sorted,sort_idx,version)&