From b79ff2ee6b32e9d1ddcd339b8102f7205367d5db Mon Sep 17 00:00:00 2001
From: Anouar Benali <abenali@gmail.com>
Date: Fri, 21 Apr 2017 10:16:20 -0500
Subject: [PATCH] Add correlation_energy_ratio_max as an exit criterion

---
 plugins/Full_CI_ZMQ/fci_zmq.irp.f | 23 ++++++++++++++++++++++-
 plugins/Perturbation/EZFIO.cfg    | 10 +++++++++-
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/plugins/Full_CI_ZMQ/fci_zmq.irp.f b/plugins/Full_CI_ZMQ/fci_zmq.irp.f
index fcc38954..9337834f 100644
--- a/plugins/Full_CI_ZMQ/fci_zmq.irp.f
+++ b/plugins/Full_CI_ZMQ/fci_zmq.irp.f
@@ -9,7 +9,13 @@ program fci_zmq
   double precision               :: threshold_davidson_in
   
   allocate (pt2(N_states))
-  
+
+  IF (correlation_energy_ratio_max .NE. 1.d0) THEN
+ 
+    DOUBLE PRECISION :: hf_energy_ref
+    CALL ezfio_get_hartree_fock_energy(hf_energy_ref)
+  END IF
+
   pt2 = 1.d0
   threshold_davidson_in = threshold_davidson
   threshold_davidson = threshold_davidson_in * 100.d0
@@ -41,8 +47,23 @@ program fci_zmq
   E_CI_before(1:N_states) = CI_energy(1:N_states)
   n_det_before = 0
   
+
   do while ( (N_det < N_det_max) .and. (maxval(abs(pt2(1:N_states))) > pt2_max) )
+
+
+    IF (correlation_energy_ratio_max .NE. 1.d0) THEN
+      DOUBLE PRECISION :: correlation_energy_var, correlation_energy_var_ratio
+
+      correlation_energy_var = MAXVAL(E_CI_before) - hf_energy_ref
+      correlation_energy_var_ratio = correlation_energy_var / (correlation_energy_var + MAXVAL(pt2(:)))
+
+      IF (correlation_energy_ratio_max < correlation_energy_var_ratio) THEN
+        EXIT
+      ENDIF
     
+    ENDIF
+ 
+ 
     print *,  'N_det          = ', N_det
     print *,  'N_states       = ', N_states
     do k=1, N_states
diff --git a/plugins/Perturbation/EZFIO.cfg b/plugins/Perturbation/EZFIO.cfg
index 4f0457a2..0477e87b 100644
--- a/plugins/Perturbation/EZFIO.cfg
+++ b/plugins/Perturbation/EZFIO.cfg
@@ -14,10 +14,18 @@ default: 0.0001
 [var_pt2_ratio]
 type: Normalized_float
 doc: The selection process stops when the energy ratio variational/(variational+PT2)
-     is equal to var_pt2_ratio
+     is equal to var_pt2_ratio. (Obsolete. Need to be removed)
 interface: ezfio,provider,ocaml
 default: 0.75
 
+[correlation_energy_ratio_max]
+type: Normalized_float
+doc: The selection process stops at a fixed correlation ratio (usefull for getting same accuracy between molecules)
+     Defined as (E_CI-E_HF)/ (E_CI+PT2 - E_HF)
+     If Ratio==1 it will not be used. (E_HF) is not required. 
+interface: ezfio,provider,ocaml
+default: 1.00
+
 [threshold_generators_pt2]
 type: Threshold
 doc: Thresholds on generators (fraction of the norm) for final PT2 calculation