From 0c40b766d224202b2aee5800eed55a77daeb9dd4 Mon Sep 17 00:00:00 2001
From: msoroush <fj2314@wayne.edu>
Date: Sun, 6 Oct 2019 13:58:38 -0400
Subject: [PATCH] Suggested fix to the issue #143 and #123

---
 src/CellList.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/CellList.h b/src/CellList.h
index 88c9748b3..09da998e9 100644
--- a/src/CellList.h
+++ b/src/CellList.h
@@ -85,6 +85,12 @@ inline int CellList::PositionToCell(const XYZ& posRef, int box) const
   int x = (int)(pos.x / cellSize[box].x);
   int y = (int)(pos.y / cellSize[box].y);
   int z = (int)(pos.z / cellSize[box].z);
+  //Check the cell number to avoid segfult for coordinates close to axis
+  //x, y, and z should never be equal or greater than number of cells in x, y, 
+  // and z axis, respectively.
+  x -= (x == edgeCells[box][0] ?  1 : 0);
+  y -= (y == edgeCells[box][1] ?  1 : 0);
+  z -= (z == edgeCells[box][2] ?  1 : 0);
   return x * edgeCells[box][1] * edgeCells[box][2] + y * edgeCells[box][2] + z;
 }