}
if (max_dist2 >= 0 && dr2 > 0.98*0.98*max_dist2)
{
- gmx_fatal(FARGS, "Distance between pull groups %d and %d (%f nm) is larger than 0.49 times the box size (%f)",
+ gmx_fatal(FARGS, "Distance between pull groups %d and %d (%f nm) is larger than 0.49 times the box size (%f).\nYou might want to consider using \"pull-geometry = direction-periodic\" instead.\n",
pcrd->group[0], pcrd->group[1], sqrt(dr2), sqrt(max_dist2));
}