From 3eaec5521569085a3c6c77308d965edef10fa5bd Mon Sep 17 00:00:00 2001
From: Anthony Scemama <scemama@irsamc.ups-tlse.fr>
Date: Mon, 30 May 2016 00:42:39 +0200
Subject: [PATCH] Forgot file

---
 plugins/Full_CI/full_ci_dressed.irp.f | 127 ++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 plugins/Full_CI/full_ci_dressed.irp.f

diff --git a/plugins/Full_CI/full_ci_dressed.irp.f b/plugins/Full_CI/full_ci_dressed.irp.f
new file mode 100644
index 00000000..6af3077f
--- /dev/null
+++ b/plugins/Full_CI/full_ci_dressed.irp.f
@@ -0,0 +1,127 @@
+program full_ci
+  implicit none
+  integer                        :: i,k
+
+  
+  double precision, allocatable  :: pt2(:), norm_pert(:), H_pert_diag(:)
+  double precision, allocatable  :: pt2_generators(:,:), norm_pert_generators(:,:), H_pert_diag_generators(:,:)
+  integer                        :: N_st, degree
+  N_st = N_states
+  allocate (pt2(N_st), norm_pert(N_st),H_pert_diag(N_st))
+  character*(64)                 :: perturbation
+  
+  pt2 = 1.d0
+  diag_algorithm = "Lapack"
+  
+  if (N_det > N_det_max) then
+    call diagonalize_CI
+    call save_wavefunction
+    psi_det = psi_det_sorted
+    psi_coef = psi_coef_sorted
+    N_det = N_det_max
+    soft_touch N_det psi_det psi_coef
+    call diagonalize_CI
+    call save_wavefunction
+    print *,  'N_det    = ', N_det
+    print *,  'N_states = ', N_states
+    print *,  'PT2      = ', pt2
+    print *,  'E        = ', CI_energy
+    print *,  'E+PT2    = ', CI_energy+pt2
+    print *,  '-----'
+  endif
+  double precision :: i_H_psi_array(N_states),diag_H_mat_elem,h,i_O1_psi_array(N_states)
+  double precision :: E_CI_before(N_states)
+  if(read_wf)then
+   call i_H_psi(psi_det(1,1,N_det),psi_det,psi_coef,N_int,N_det,psi_det_size,N_states,i_H_psi_array)
+   h = diag_H_mat_elem(psi_det(1,1,N_det),N_int)
+   selection_criterion = dabs(psi_coef(N_det,1) *  (i_H_psi_array(1) - h * psi_coef(N_det,1))) * 0.1d0
+   soft_touch selection_criterion
+  endif
+
+
+  integer :: n_det_before
+  print*,'Beginning the selection ...'
+  E_CI_before = CI_energy
+  do while (N_det < N_det_max.and.maxval(abs(pt2(1:N_st))) > pt2_max)
+    n_det_before = N_det
+    call H_apply_FCI(pt2, norm_pert, H_pert_diag,  N_st)
+
+    PROVIDE  psi_coef
+    PROVIDE  psi_det
+    PROVIDE  psi_det_sorted
+
+    if (N_det > N_det_max) then
+       psi_det = psi_det_sorted
+       psi_coef = psi_coef_sorted
+       N_det = N_det_max
+       soft_touch N_det psi_det psi_coef
+    endif
+    call diagonalize_CI
+    call save_wavefunction
+    if(n_det_before == N_det)then
+     selection_criterion = selection_criterion * 0.5d0
+    endif
+    print *,  'N_det          = ', N_det
+    print *,  'N_states       = ', N_states
+    do  k = 1, N_states
+    print*,'State ',k
+    print *,  'PT2            = ', pt2(k)
+    print *,  'E              = ', CI_energy(k)
+    print *,  'E(before)+PT2  = ', E_CI_before(k)+pt2(k)
+    enddo
+    print *,  '-----'
+    E_CI_before = CI_energy
+    if(N_states.gt.1)then
+     print*,'Variational Energy difference'
+     do i = 2, N_states
+      print*,'Delta E = ',CI_energy(i) - CI_energy(1)
+     enddo
+    endif
+    if(N_states.gt.1)then
+     print*,'Variational + perturbative Energy difference'
+     do i = 2, N_states
+      print*,'Delta E = ',E_CI_before(i)+ pt2(i) - (E_CI_before(1) + pt2(1))
+     enddo
+    endif
+    E_CI_before = CI_energy
+    call ezfio_set_full_ci_energy(CI_energy)
+  enddo
+   N_det = min(N_det_max,N_det)
+   touch N_det psi_det psi_coef
+   call diagonalize_CI
+   if(do_pt2_end)then
+    threshold_selectors = 1.d0
+    threshold_generators = 0.999d0
+    TOUCH threshold_selectors threshold_generators
+    allocate (pt2_generators(N_st,N_det_generators), norm_pert_generators(N_st,N_det_generators),H_pert_diag_generators(N_st,N_det_generators))
+    call H_apply_FCI_PT2_dressed(pt2_generators, norm_pert_generators, H_pert_diag_generators,  N_st)
+    psi_det = psi_det_sorted
+    psi_coef = psi_coef_sorted
+    SOFT_TOUCH psi_det psi_coef
+    double precision, allocatable :: energy(:), dressing(:)
+    allocate(energy(N_states), dressing(N_det))
+    do k=1,N_det_generators
+      dressing(k) = pt2_generators(1,k)
+    enddo
+    do k=N_det_generators+1,N_det
+      dressing(k) = 0.d0
+    enddo
+
+    print *,  'Final step'
+    print *,  'N_det    = ', N_det
+    print *,  'N_states = ', N_states
+    print *,  'PT2      = ', sum(dressing)
+    print *,  'E    = ', CI_energy
+    print *,  'E+PT2= ', CI_energy + sum(dressing)
+
+    call davidson_diag_dressed(dressing,psi_det,psi_coef,energy, &
+        size(psi_det,1),N_det,N_states_diag,N_int,output_determinants)
+ 
+    print *,  'E dressed = ', energy
+    print *,  '----------- '
+    call ezfio_set_full_ci_energy_pt2(energy)
+    deallocate(pt2_generators,norm_pert_generators)
+   endif
+   call save_wavefunction
+  deallocate(pt2,norm_pert)
+end