diff --git a/modules/conop/src/conop.cc b/modules/conop/src/conop.cc
index 3267e83e059ecffbeb3490ea18a01994ad5d8599..cb19a99bf32e458f88cd81c221a82f5bb2b83ba5 100644
--- a/modules/conop/src/conop.cc
+++ b/modules/conop/src/conop.cc
@@ -42,7 +42,7 @@ Conopology::Conopology():
 
   ele_rad_map_["H"]  = 1.09;
                  
-  ele_rad_map_["C"]  = 1.75;
+  ele_rad_map_["C"]  = 1.70;  //was 1.75
   ele_rad_map_["N"]  = 1.55;
   ele_rad_map_["O"]  = 1.52;
   ele_rad_map_["F"]  = 1.47;