I've performed an adsorption isotherm task and would like to know what sort of analysis, if any, I can do to the density field of the sorbate that has been generated. The framework is amorphous and there is a single pore that looks a bit like a network. The diameter of this pore varies such that it can be thought of as interconnected pores of various sizes. 

I've noticed that the density field is included in the create segregates button on the volume visualisation toolbar but when I try to segregate the density field I get the error 'bad allocation' then MS hangs. I can however create isosurfaces of the density field, not that I can see how that would help me with analysis though.

What I would really like to do is to try and see if sorption at the low pressures of the isotherm occurs in smaller pores before larger ones. I can analyse the pore structure using the segregates once I've created an atom volumes and surfaces isosurface. One slight problem here is that the pores are interconnected and I would have to fiddle with the radius of the probe used to generate pores isosurface.

I had thought that placing a probe molecule at the centre of each sorbate density 'cluster' and increasing the radius of the probe until it overlaps with the framework atoms but again I don't see how this would be possible.

Any suggestions on how to use materials studio to analyse which pores are preferential to adsorption would be appreciated.