From cc0e17b9326346e4b1561f7a2ceb3f8efba14529 Mon Sep 17 00:00:00 2001
From: Sebastian Ehlert <28669218+awvwgk@users.noreply.github.com>
Date: Thu, 21 Oct 2021 14:52:22 +0200
Subject: [PATCH 1/2] Make sure to not allow filling more electrons than
 orbitals available

---
 src/scf_module.F90 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/scf_module.F90 b/src/scf_module.F90
index 8ddeb86ea..c475d4648 100644
--- a/src/scf_module.F90
+++ b/src/scf_module.F90
@@ -336,6 +336,10 @@ subroutine scf(env, mol, wfn, basis, pcem, xtbData, solvation, &
 
    ! fill levels
    if(wfn%nel.ne.0) then
+      if (wfn%nel > 2*size(basis%nao)) then
+         call env%error("Not enough basis functions for filling orbitals", source)
+         return
+      end if
       call occu(basis%nao,wfn%nel,wfn%nopen,wfn%ihomoa,wfn%ihomob,wfn%focca,wfn%foccb)
       wfn%focc = wfn%focca + wfn%foccb
       wfn%ihomo=wfn%ihomoa

From b42d9ebf041632b09836bbd31b3fe47b284b806b Mon Sep 17 00:00:00 2001
From: Sebastian Ehlert <28669218+awvwgk@users.noreply.github.com>
Date: Thu, 21 Oct 2021 16:34:46 +0200
Subject: [PATCH 2/2] Fix error

---
 src/scf_module.F90 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/scf_module.F90 b/src/scf_module.F90
index c475d4648..7098dbb68 100644
--- a/src/scf_module.F90
+++ b/src/scf_module.F90
@@ -336,7 +336,7 @@ subroutine scf(env, mol, wfn, basis, pcem, xtbData, solvation, &
 
    ! fill levels
    if(wfn%nel.ne.0) then
-      if (wfn%nel > 2*size(basis%nao)) then
+      if (wfn%nel > 2*basis%nao) then
          call env%error("Not enough basis functions for filling orbitals", source)
          return
       end if