[PyMOL] Pseudoatom for Benzene Centre

[imtiaz <bio...@gm...>]

I want to create a Pseudoatom in the center of a benzene ring for a ligand.

I can easily create a Pseudoatom in the center of aromatic ring of
amino acids in a protein by following the instructions give at

http://www.pymolwiki.org/index.php/Pseudoatom

i.e
load $TUT/1hpv.pdb
pseudoatom pi_cent,b/53/cg+cz


However I am not sure how I can do similar thing for the lignad. The
lignad I have is an indole derivative and I want to create a
pseudoatom in the center of the 6 member ring of the indole.

Please suggest me some thing how I can use selection of this ring to
create a pseudoatom in the center.

Kind Regards
Imtiaz