Calculate the occupied volume of the .xtd file

Hello everybody,

After I run a dynamic simulation of a polymer, the Materials Studio will output one .xtd file, with many frames showing how polymer chains change over time. Now I want to create a Connolly surface for each frame to calculate FFV. 

However, in the script I have, I can only calculate the free volume, not the occupied volume.
So, is there a way, for example, to write a script that does what I want?

Thank you in advance, hope to get your help.