From 88c47b1f73370cdad670b16807c32d6ff8d7c6d8 Mon Sep 17 00:00:00 2001
From: Anthony Scemama <scemama@irsamc.ups-tlse.fr>
Date: Fri, 27 Nov 2015 10:30:50 +0100
Subject: [PATCH] Trap linear dependencies in basis set

---
 src/AO_Basis/ao_overlap.irp.f   | 1 -
 src/MOGuess/guess_overlap.irp.f | 1 +
 src/Utils/LinearAlgebra.irp.f   | 4 ++--
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/AO_Basis/ao_overlap.irp.f b/src/AO_Basis/ao_overlap.irp.f
index 9b3fa7e9..4487ff77 100644
--- a/src/AO_Basis/ao_overlap.irp.f
+++ b/src/AO_Basis/ao_overlap.irp.f
@@ -60,7 +60,6 @@
   enddo
   !$OMP END PARALLEL DO
 
-  ! Check for linear dependencies in the basis set
 END_PROVIDER
 
 
diff --git a/src/MOGuess/guess_overlap.irp.f b/src/MOGuess/guess_overlap.irp.f
index cf222507..c2f090e5 100644
--- a/src/MOGuess/guess_overlap.irp.f
+++ b/src/MOGuess/guess_overlap.irp.f
@@ -4,6 +4,7 @@ program guess_mimi
   END_DOC
   implicit none
   character*(64)                 :: label
+
   mo_coef = ao_ortho_lowdin_coef
   TOUCH mo_coef
   label = "Guess"
diff --git a/src/Utils/LinearAlgebra.irp.f b/src/Utils/LinearAlgebra.irp.f
index c5e66006..dab9e921 100644
--- a/src/Utils/LinearAlgebra.irp.f
+++ b/src/Utils/LinearAlgebra.irp.f
@@ -82,8 +82,8 @@ subroutine ortho_lowdin(overlap,LDA,N,C,LDC,m)
 
   !$OMP DO
   do i=1,n
-    if ( D(i) < 1.d-6 ) then
-      D(i) = 0.d0
+    if ( D(i) < 1.d-12 ) then
+      stop 'Linear dependence in basis set'
     else
       D(i) = 1.d0/dsqrt(D(i))
     endif