From a51108ba42527a026fe30a38c5d04a5d320c08ed Mon Sep 17 00:00:00 2001
From: Patrick Shriwise <pshriwise@gmail.com>
Date: Wed, 23 Oct 2019 16:33:18 -0500
Subject: [PATCH] Remove un-needed indexing of nuclide value.

---
 openmc/mgxs/library.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/openmc/mgxs/library.py b/openmc/mgxs/library.py
index fbf08f85f7..83d3178ff7 100644
--- a/openmc/mgxs/library.py
+++ b/openmc/mgxs/library.py
@@ -986,7 +986,7 @@ class Library(object):
             xsdata.num_azimuthal = self.num_azimuthal
 
         if nuclide != 'total':
-            xsdata.atomic_weight_ratio = self._nuclides[nuclide][1]
+            xsdata.atomic_weight_ratio = self._nuclides[nuclide]
 
         if subdomain is None:
             subdomain = 'all'