From 968e56694ff0a5bb2f87958265f1c8c2a399d3ec Mon Sep 17 00:00:00 2001
From: Evangelos Voyiatzis <evoyiatzis@gmail.com>
Date: Mon, 17 Dec 2018 18:02:27 +0100
Subject: [PATCH] Update pair_lj_class2.cpp

---
 src/CLASS2/pair_lj_class2.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/CLASS2/pair_lj_class2.cpp b/src/CLASS2/pair_lj_class2.cpp
index 6451921dc5..e6546b1acc 100644
--- a/src/CLASS2/pair_lj_class2.cpp
+++ b/src/CLASS2/pair_lj_class2.cpp
@@ -14,6 +14,7 @@
 #include <cmath>
 #include <cstdio>
 #include <cstdlib>
+#include <cstring>
 #include "pair_lj_class2.h"
 #include "atom.h"
 #include "comm.h"
@@ -394,3 +395,13 @@ double PairLJClass2::single(int /*i*/, int /*j*/, int itype, int jtype, double r
     offset[itype][jtype];
   return factor_lj*philj;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void *PairLJClass2::extract(const char *str, int &dim)
+{
+  dim = 2;
+  if (strcmp(str,"epsilon") == 0) return (void *) epsilon;
+  if (strcmp(str,"sigma") == 0) return (void *) sigma;
+  return NULL;
+}