From 9bf0590cbab4eb7ece77884743e1e3d3dd3b58d6 Mon Sep 17 00:00:00 2001
From: Geoff Hutchison <geoff.hutchison@gmail.com>
Date: Mon, 11 Sep 2023 10:04:40 -0400
Subject: [PATCH] Fix autodetect for force field

Fix #1324 by ignoring MMFF94 support for iron, etc.
(MMFF94 only supports isolated ions.)

Signed-off-by: Geoff Hutchison <geoff.hutchison@gmail.com>
---
 avogadro/qtplugins/openbabel/openbabel.cpp | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/avogadro/qtplugins/openbabel/openbabel.cpp b/avogadro/qtplugins/openbabel/openbabel.cpp
index 05ab620a53..fc00590de3 100644
--- a/avogadro/qtplugins/openbabel/openbabel.cpp
+++ b/avogadro/qtplugins/openbabel/openbabel.cpp
@@ -837,13 +837,10 @@ QString OpenBabel::autoDetectForceField() const
         *eleIter != "N" && *eleIter != "O" && *eleIter != "P" &&
         *eleIter != "S") {
       gaffValid = false;
+      mmff94Valid = false;
 
-      // These are supported by MMFF94 (but not GAFF)
-      if (*eleIter != "Fe" && *eleIter != "Li" && *eleIter != "Na" &&
-          *eleIter != "K" && *eleIter != "Zn" && *eleIter != "Ca" &&
-          *eleIter != "Cu" && *eleIter != "Mg" && *eleIter != "Na") {
-        mmff94Valid = false;
-      }
+      // MMFF94 supports isolated metal ions but it's safer to use UFF
+      // Fixes #1324
     }
     ++eleIter;
   }