From a460863632d43a0c4aecb2f0d64ca68c835a5ab2 Mon Sep 17 00:00:00 2001
From: Anthony Scemama <scemama@irsamc.ups-tlse.fr>
Date: Mon, 25 May 2020 23:32:23 +0200
Subject: [PATCH] DIIS stability

---
 src/scf_utils/roothaan_hall_scf.irp.f | 23 +++++------------------
 1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/src/scf_utils/roothaan_hall_scf.irp.f b/src/scf_utils/roothaan_hall_scf.irp.f
index d332a75c..e78630c2 100644
--- a/src/scf_utils/roothaan_hall_scf.irp.f
+++ b/src/scf_utils/roothaan_hall_scf.irp.f
@@ -277,7 +277,7 @@ END_DOC
     return
   endif
 
- if (rcond < 1.d-10) then
+ if (rcond == 0.d-10) then
    dim_DIIS = 0
    return
  endif
@@ -287,25 +287,12 @@ END_DOC
   X_vector_DIIS = C_vector_DIIS
   call dgesv ( dim_DIIS+1 , 1, B_matrix_DIIS, size(B_matrix_DIIS,1), &
       ipiv , X_vector_DIIS , size(X_vector_DIIS,1), info)
-!  call dsysvx('N','U',dim_DIIS+1,1,      &
-!   B_matrix_DIIS,size(B_matrix_DIIS,1), &
-!   AF, size(AF,1),                      &
-!   ipiv,                                &
-!   C_vector_DIIS,size(C_vector_DIIS,1), &
-!   X_vector_DIIS,size(X_vector_DIIS,1), &
-!   rcond,                               &
-!   ferr,                                &
-!   berr,                                &
-!   scratch,size(scratch),               &
-!   iwork,                               &
-!   info                                 &
-! )
 
- deallocate(scratch,AF,iwork)
+  deallocate(scratch,AF,iwork)
 
- if(info < 0) then
-   stop 'bug in DIIS'
- endif
+  if(info < 0) then
+    stop 'bug in DIIS'
+  endif
 
   ! Compute extrapolated Fock matrix