Made g_sgangle fatal error a bit more verbose.

diff --git a/src/tools/gmx_sgangle.c b/src/tools/gmx_sgangle.c
index fd214858614e9f6e7db66e597ee0b9c03326c1e4..47ab299246f03ee7bee30c53e30c7a2ee6a39c1e 100644 (file)
--- a/src/tools/gmx_sgangle.c
+++ b/src/tools/gmx_sgangle.c
@@ -124,7 +124,7 @@ static void calc_angle(int ePBC,matrix box,rvec x[], atom_id index1[],
       svmul(0.5,h1,center1);  /* center is geometric mean */
       break;
     default:          /* group 1 does none of the above */
-      gmx_fatal(FARGS,"Something wrong with contents of index file.\n");
+      gmx_fatal(FARGS,"Something wrong with contents of index file. Groups should contain 2 or 3 atoms.\n");
     }
 
   switch(gnx2)