diff --git a/src/Determinants/s2.irp.f b/src/Determinants/s2.irp.f
index 400b373e..e16bd386 100644
--- a/src/Determinants/s2.irp.f
+++ b/src/Determinants/s2.irp.f
@@ -301,19 +301,19 @@ subroutine diagonalize_s2_betweenstates(keys_tmp,psi_coefs_inout,n,nmax_keys,nma
  print*,''
  print*,'nstates = ',nstates
  allocate(s2(nstates,nstates),overlap(nstates,nstates))
- !$OMP PARALLEL DO COLLAPSE(2) DEFAULT(NONE) &
- !$OMP  PRIVATE(i,j) SHARED(overlap,psi_coefs_inout,nstates,n)
-  do i = 1, nstates
-    do j = i+1, nstates
-      if (i == j) then
-        overlap(i,i) = u_dot_u(psi_coefs_inout(1,i),n)
-      else
-        overlap(i,j) = u_dot_v(psi_coefs_inout(1,j),psi_coefs_inout(1,i),n)
-        overlap(j,i) = overlap(i,j)
-      endif
-    enddo
-  enddo
-  !$OMP END PARALLEL
+ !$OMP PARALLEL DO COLLAPSE(2) DEFAULT(NONE)                         &
+     !$OMP  PRIVATE(i,j) SHARED(overlap,psi_coefs_inout,nstates,n)
+ do i = 1, nstates
+   do j = i+1, nstates
+     if (i == j) then
+       overlap(i,i) = u_dot_u(psi_coefs_inout(1,i),n)
+     else
+       overlap(i,j) = u_dot_v(psi_coefs_inout(1,j),psi_coefs_inout(1,i),n)
+       overlap(j,i) = overlap(i,j)
+     endif
+   enddo
+ enddo
+ !$OMP END PARALLEL DO
  print*,'Overlap matrix in the basis of the states considered'
  do i = 1, nstates
   write(*,'(10(F16.10,X))')overlap(i,:)