Morphology Calculations: need help in setting up the structure

Hi,

I am a newbie and need an expert help.  I am trying to reproduce morphology calculations on ZIF-7 nanocrystals as reported on Adv. Mater. 2010, 3322-3326 (DOI: 10.1002/adma.201000857).  I have the structure of the crystal in CIF format and was able to optimize the geometries using Forcite.  However, when I tried running Growth Morphology calculations, I encountered the following error:  "The input crystal contains an infinite network of atoms.  The calculations require that the crystal is formed from isolated molecules".   I really appreciate it if someone can give me an idea on how to resolve this problem.  

thanks,

--Her