Subject: equilibrium and MD of liquids

From: [email-masked] (Ross Underhill)
Date: Thu, 15 Dec 1994 14:53:24 -0500

I'm engaged in trying to obtain the solubility of some large
molecules in different solvents to understand the effect of solvent shape
and size.  The approach I'm trying to use is to bring a large periodic box
of solvent molecules containing a single solute molecule into equilibrium
and obtain the energy of the system suing MD.  As a start I am trying to
bring just a large periodic box of solvent into equilibrium.  Suffice it to
say I've found some interesting effects.  In particular it would seem that
it is very easy to get hung up in local miminima.  I seem to get get
convergence to a global minimum much faster if I compress the model into a
smaller volume than desired, do a little relaxation and then increase the
volume to the final value for the full MD run.   Is anyone aware of any
other tricks one can do to increase the speed of convergence to equilibrium,
or more important avoid falling into a local minimum.  I would appreciate
any pointers or references I could get.

Thanks in advance

Dr. Ross Underhill
Royal Military College of Canada
Kingston, Ontario
(613) 541-6000 X6175