From fc815fc0a4e73ac768b85f99a686a610a9c6313d Mon Sep 17 00:00:00 2001
From: Max Liu <mjliu@mit.edu>
Date: Thu, 4 Apr 2019 18:12:32 -0400
Subject: [PATCH] Sort reaction species by index

---
 rmgpy/rmg/model.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rmgpy/rmg/model.py b/rmgpy/rmg/model.py
index 037ea8af0c4..0134168a51b 100644
--- a/rmgpy/rmg/model.py
+++ b/rmgpy/rmg/model.py
@@ -361,8 +361,8 @@ def checkForExistingReaction(self, rxn):
         """
 
         # Make sure the reactant and product lists are sorted before performing the check
-        rxn.reactants.sort()
-        rxn.products.sort()
+        rxn.reactants.sort(key=lambda x: x.index)
+        rxn.products.sort(key=lambda x: x.index)
 
         # If reactants and products are identical, then something weird happened along
         # the way and we got a symmetrical reaction.