RDF?

Hello everyone,
I hope you are great.
I have a box of polymer with the RDF that I attached below.
I used the sorption module for investigating CO2 adsorption. After that, I ran the NVT ensemble to access the .xtd file, used the Find pattern, selected CO2 molecules, and tried to plot the RDF of CO2 in the polymer. But, I think the result is strange!
I would appreciate it if someone tells what I am doing wrong?
Best regards,
Ali