Arik: Your topology file(s) are welcome in order to provide help. Vitaly > I'll be most thankful for any comment/help you might have regarding the > following error that I'm encountering in grompp_d : > > Atomtype amber99_34 not found > > In ffamber99sb.rtp, amber99_34 refers to the N atom of each amino acid. > > Thanks a lot > > Arik