[gmx-users] Alternative TRP residue

[abelius]

Dear All,

I have AmberFF parameters for a TRP excited state and I was wondering if 
it was possible to create an alternative TRP residue for gromacs?
Things I've done so far:
* Download and install amber99 for gromacs
* Add a new residue [ ETRP ] with adapted charges to the amber99.rtp file
* Add ETRP to aminoacids.dat

My question is where do I go from here, how can I add distances (bond 
lengths) and angles?

Thank you very much,
Abel