AMBER Archive (2002)

Subject: Image charges with the solvate cap command

From: dkeller_at_unm.edu
Date: Mon Sep 30 2002 - 10:52:11 CDT

Hi,

Our system is very large so we are trying to hydrate just the part of
greatest interest with a water cap, and freeze the rest. But a back -
of-the-envelope calculation says that any time you use a water cap
there should be a large image potential acting on any charged particle,
due to the discontinuity in the dielectric constant at the surface of
the cap. Worse, the image charge due to one real charged particle
should also affect all the other real charged particles. I haven't
seen any mention of this in the literature, and I know people use water
caps all the time. Is there some reason why the image forces don't
happen in AMBER (say, with TIPS3P water), or is there some trick to
deal with them (or cancel them)?

Thanks