I have a protein and I want to check the orientation of side chain of a particular resdiue with respect to the residue in the active site. any help on this regard? currently I am using gmx gangel where the group 1 includes the alpha carbon position of active side residue and alpha carbon of the other residue and group 2 include alpha carbon of active residue and the last atom of the other residue. i am not sure if this is the correct way. any guidance would be appreciated.