compute rdf

Hi Dear

I simulate a box containing a particle in center and polymer chains around it. Then I have two group:1-polymer group and 2- particle group. The atom types of group1 are 17 and the atom types of group2 are 89.

The pair_style which I used is following:

pair_style lj/cut/coul/cut 10.5 4.5

If I want to calculate RDF between particle and polymer chains by “compute rdf” command. I want to calculate rdf from particle surface up to 30 Angstrom.
My question is whether the following command line is correct?

compute myrdf resin rdf 100 89 17

I used but the answer not logical, because I expected rdf in VDW bap is zero, but did not.