Dear Accelrys Community

I have this strange problem with Sorption module in Materials Studio.

I am trying to calculate CO2 sorption isotherms on a polymer system and the results it gives me are way lower than the ones obtained experimentally [almost by an order of magnitude].

I have tried two polymer systems [rubbery and glassy] as well as bunch of forcefields [pcff and compass]. I have even changed a lot of parameters in the sorption module [like Exchange ratio, Conformer, rotate etc] but still get low values for sorption.

I need your expert help to see what I am doing wrong.

All my polymer systems are equilibrated for long times using simulated annealing, minimization and the usual published steps.

I get the right density and other properties for the polymer systems ... which basically means that my structures are right.

I still don't understand what I am doing wrong?

Thanks

Mayur