[gmx-users] modifying LJ interactions in Hamiltonian REMD

[Jens Kahlen]

Dear all,

I am trying to set up a Hamiltonian REMD simulation of a peptide
interacting with ions in solution. In order to avoid salt bridges and
thus to increase the conformational sampling, my idea was to weaken the
LJ interactions between the oxygen atoms of the side chains and the
cations in solution. However, after studying the manual and the mailing
list, I still haven't been able to figure out the proper way to define
the modified LJ parameters of the oxygen-cation interactions in state B.

Is there a simple way of doing this or do I need to define a new atomtype?

Thanks in advance,

Jens