From bc626377f389c9f1b40a1625584731314010e80f Mon Sep 17 00:00:00 2001
From: Yann Garniron <yann.garniron@yahoo.fr>
Date: Mon, 5 Mar 2018 12:43:31 +0100
Subject: [PATCH] shiftedbk not working - may be removed later

---
 plugins/shiftedbk/shifted_bk.irp.f | 52 +++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 11 deletions(-)

diff --git a/plugins/shiftedbk/shifted_bk.irp.f b/plugins/shiftedbk/shifted_bk.irp.f
index 12c867d6..4b9c7433 100644
--- a/plugins/shiftedbk/shifted_bk.irp.f
+++ b/plugins/shiftedbk/shifted_bk.irp.f
@@ -8,12 +8,9 @@ program mrcc_sto
 end
 
 
-! BEGIN_PROVIDER [ double precision, hij_cache_, (N_det,Nproc) ]
-!&BEGIN_PROVIDER [ double precision, sij_cache_, (N_det,Nproc) ]
  BEGIN_PROVIDER [ double precision, fock_diag_tmp_, (2,mo_tot_num+1,Nproc) ]
 &BEGIN_PROVIDER [ integer, current_generator_, (Nproc) ]
   implicit none
-!  allocate(fock_diag_tmp(2,mo_tot_num+1))
   current_generator_(:) = 0
  END_PROVIDER
 
@@ -25,6 +22,7 @@ subroutine dress_with_alpha_buffer(delta_ij_loc, i_gen, minilist, det_minilist,
   BEGIN_DOC
   !delta_ij_loc(:,:,1) : dressing column for H
   !delta_ij_loc(:,:,2) : dressing column for S2
+  !i_gen : generator index in psi_det_generators
   !minilist : indices of determinants connected to alpha ( in psi_det_sorted )
   !n_minilist : size of minilist
   !alpha : alpha determinant
@@ -35,21 +33,31 @@ subroutine dress_with_alpha_buffer(delta_ij_loc, i_gen, minilist, det_minilist,
   double precision :: hii, hij, sij, delta_e
   double precision, external :: diag_H_mat_elem_fock
   integer                        :: i,j,k,l,m, l_sd
+  double precision, save :: tot = 0d0
+  double precision :: de(N_states), val, tmp
   
+  stop "shiftedbk currently does not work"
 
   if(current_generator_(iproc) /= i_gen) then
     current_generator_(iproc) = i_gen
     call build_fock_tmp(fock_diag_tmp_(1,1,iproc),psi_det_generators(1,1,i_gen),N_int)
   end if
-  !return
-  hii = diag_H_mat_elem_fock(psi_det_generators(1,1,i_gen),alpha,fock_diag_tmp_(1,1,iproc),N_int)
-  
 
-  do l_sd=1,n_minilist
-    call i_h_j_s2(alpha,det_minilist(1,1,l_sd),N_int,hij, sij)
-    do i=1,N_states
-      delta_ij_loc(i, minilist(l_sd), 1) += hij / hii * psi_coef(minilist(l_sd), i)
+  hii = diag_H_mat_elem_fock(psi_det_generators(1,1,i_gen),alpha,fock_diag_tmp_(1,1,iproc),N_int)
+  do i=1,N_states
+    de(i) = (E0_denominator(i) - hii)
+  end do
+  
+  do i=1,N_states
+    val = 0D0
+    do l_sd=1,n_minilist
+      call i_h_j_s2(alpha,det_minilist(1,1,l_sd),N_int,hij, sij)
+      val += hij
     end do
+    val = 2d0 * val
+    tmp = dsqrt(de(i)**2 + val**2)
+    if(de(i) < 0d0) tmp = -tmp
+    delta_ij_loc(i, minilist(l_sd), 1) += 0.5d0 * (tmp - de(i)) ! * psi_coef(minilist(l_sd), i)
   end do
 end subroutine
 
@@ -57,4 +65,26 @@ end subroutine
 
 
 
-
+BEGIN_PROVIDER [ logical, initialize_E0_denominator ]
+    implicit none
+    BEGIN_DOC
+    ! If true, initialize pt2_E0_denominator
+    END_DOC
+    initialize_E0_denominator = .True.
+END_PROVIDER
+   
+BEGIN_PROVIDER [ double precision, E0_denominator, (N_states) ]
+  implicit none
+  BEGIN_DOC
+  ! E0 in the denominator of the PT2
+  END_DOC
+  if (initialize_E0_denominator) then
+   E0_denominator(1:N_states) = psi_energy(1:N_states)
+ ! call ezfio_get_full_ci_zmq_energy(pt2_E0_denominator(1))
+ ! pt2_E0_denominator(1) -= nuclear_repulsion
+ ! pt2_E0_denominator(1:N_states) = HF_energy - nuclear_repulsion
+ ! pt2_E0_denominator(1:N_states) = barycentric_electronic_energy(1:N_states)
+  else
+    E0_denominator = -huge(1.d0)
+  endif
+END_PROVIDER