From 412cb8f089bb9e3b2ae5cfc49bc310fa38425c32 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Tue, 30 May 2017 08:15:55 -0400
Subject: [PATCH] avoid hang in fix reax/c/species when multiple atoms have the
 exact same x-coordinate

---
 src/USER-REAXC/fix_reaxc_species.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/USER-REAXC/fix_reaxc_species.cpp b/src/USER-REAXC/fix_reaxc_species.cpp
index fe74337128..4e57dd1c4b 100644
--- a/src/USER-REAXC/fix_reaxc_species.cpp
+++ b/src/USER-REAXC/fix_reaxc_species.cpp
@@ -500,8 +500,16 @@ void FixReaxCSpecies::Output_ReaxC_Bonds(bigint ntimestep, FILE *fp)
 
 AtomCoord FixReaxCSpecies::chAnchor(AtomCoord in1, AtomCoord in2)
 {
-  if (in1.x <= in2.x)
+  if (in1.x < in2.x)
     return in1;
+  else if (in1.x == in2.x) {
+    if (in1.y < in2.y)
+      return in1;
+    else if (in1.y == in2.y) {
+      if (in1.z < in2.z)
+        return in1;
+    }
+  }
   return in2;
 }