Molecule assignement in infinite network. Problem

Hi,

I developed a script which permits to create  the cross-linked networks of thermoset resins. I want to follow the mass of the largest fragment at each reticulation step in order to estimate the gel point. My methodology is following: when two molecules react, I take away the "molecule hierarchy" from reacted molecules, after that I use the command "CreateMolecule" on all the atoms which are involved in the cross link. This happens at each reticulation step and the mass of the largest molecule is recorded.

The problem is that when the reticulation degree reaches a certain threshold, my periodic structure becomes an infinite network and the command "CreateMolecule" can't operate on this kind of structures: 

Error ----------->     "No such interface supported in CreateMolecule (function/property "CreateMolecule") ".


When I work with periodic structures this method works till 30 % of conversion and then there is the error message. The only solution I found for this problem is to work without periodicity, but it's not appropriate to compare this results with bulk.

I would be thankful for any help.

Thank you for your attention.