From bc2ecb8b2d4a1641bb9d87343bc11f7869ac5d87 Mon Sep 17 00:00:00 2001
From: Emmanuel Giner <giner.emmanuel@gmail.com>
Date: Thu, 22 Jul 2021 23:31:08 +0200
Subject: [PATCH] minor modifs in casscf

---
 devel/casscf/EZFIO.cfg    | 18 ++++++++++++++++++
 devel/casscf/casscf.irp.f | 22 ++++++++++++++++------
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/devel/casscf/EZFIO.cfg b/devel/casscf/EZFIO.cfg
index c8ce539..2a1f192 100644
--- a/devel/casscf/EZFIO.cfg
+++ b/devel/casscf/EZFIO.cfg
@@ -55,3 +55,21 @@ doc: Threshold on the convergence of the CASCF energy.
 interface: ezfio,provider,ocaml
 default: 1.e-06
 
+
+[pt2_min_casscf]
+type: Threshold
+doc: Minimum value of the pt2_max parameter for the CIPSI in the CASSCF iterations.
+interface: ezfio,provider,ocaml
+default: 1.e-04
+
+[n_big_act_orb]
+type: integer
+doc: Number of active orbitals from which the active space is considered as large, and therefore pt2_min_casscf is activated.
+interface: ezfio,provider,ocaml
+default: 16
+
+[adaptive_pt2_max]
+type: logical
+doc: If |true|, the pt2_max value in the CIPSI iterations will automatically adapt, otherwise it is fixed at the value given in the EZFIO folder
+interface: ezfio,provider,ocaml
+default: True
diff --git a/devel/casscf/casscf.irp.f b/devel/casscf/casscf.irp.f
index 03d2638..39dc94d 100644
--- a/devel/casscf/casscf.irp.f
+++ b/devel/casscf/casscf.irp.f
@@ -6,8 +6,6 @@ program casscf
   call reorder_orbitals_for_casscf
 !  no_vvvv_integrals = .True.
 !  touch no_vvvv_integrals
-  pt2_max = 0.005
-  SOFT_TOUCH pt2_max
   n_det_max_full = 500
   touch n_det_max_full
   pt2_relative_error = 0.02
@@ -30,6 +28,10 @@ subroutine run
   state_following_casscf = .True.
   touch state_following_casscf
   ept2_before = 0.d0
+  if(adaptive_pt2_max)then
+   pt2_max = 0.005
+   SOFT_TOUCH pt2_max
+  endif
   do while (.not.converged)
     call run_stochastic_cipsi
     energy_old = energy
@@ -66,8 +68,13 @@ subroutine run
      converged = dabs(delta_E) < thresh_casscf
     endif
     ept2_before = E_PT2
-    pt2_max = dabs(energy_improvement / (pt2_relative_error))
-    pt2_max = min(pt2_max, pt2_max_before)
+    if(adaptive_pt2_max)then
+     pt2_max = dabs(energy_improvement / (pt2_relative_error))
+     pt2_max = min(pt2_max, pt2_max_before)
+     if(n_act_orb.ge.n_big_act_orb)then
+      pt2_max = max(pt2_max,pt2_min_casscf)
+     endif
+    endif
     print*,''
     call write_double(6,pt2_max, 'PT2_MAX for next iteration = ')
 
@@ -76,12 +83,15 @@ subroutine run
     call save_mos
     if(.not.converged)then
      iteration += 1
-     N_det = max(N_det/2 ,N_states)
+     N_det = max(N_det/8 ,N_states)
      psi_det = psi_det_sorted
      psi_coef = psi_coef_sorted
      read_wf = .True.
      call clear_mo_map
-     SOFT_TOUCH mo_coef N_det pt2_max  psi_det psi_coef
+     SOFT_TOUCH mo_coef N_det psi_det psi_coef
+     if(adaptive_pt2_max)then
+       SOFT_TOUCH pt2_max  
+     endif
      if(iteration .gt. 3)then
       state_following_casscf = state_following_casscf_save
       soft_touch state_following_casscf