just started with MS.  Planning on using it in designing/modeling separation membranes. trying things out with MS and getting a feel for it. 

1st hurdle: can not construct an amorphous cell with more than 2 molecules (2 polyemers, 16 units each).  Tried both gateway locations (local PC and a HPC Linux server).  if i increase number of constituent molecules beyond 2, job fails...! Will appreciate any help on this?