Re: peridic boundary condition

From: Himanshu Khandelia (
Date: Fri Mar 11 2005 - 13:57:23 CST

Periodic B.C. are used so that there are no end effects on the wall of the
simulation. that is about it.

Himanshu Khandelia

Doctoral Candidate,
Kaznessis Research,
Department of Chemical Engineering and Materials Science,
University of Minnesota

Mailing Address:

499, Walter Library,
117, Pleasant St. SE,
Minneapolis, MN 55455

Phone(o): 612-624-4945

On Fri, 11 Mar 2005, Marc Q. Ma wrote:

> Ed,
> > There is a physical justification for using PBC, PBC conserve the
> > momentum of the system. It is my understanding that without PBC
> > conservation of momentum is violated.
> >
> > Ed
> For conservative systems, conservation of momentum has nothing to do
> with boundary conditions. For MD as is row, the forces are all pairwise
> additive, and F12 = -F21. Momentum is strictly conserved. I am not sure
> about polarizable force fields, I guesstimate it is still true.
> When there is random force, such as the Langevin Pistons or heat
> reservoirs, the momentum conservation is going to be violated at each
> time step.
> Marc

This archive was generated by hypermail 2.1.6 : Wed Feb 29 2012 - 15:40:35 CST