Re: A question about restaints force.

From: Gungor Ozer (
Date: Fri Apr 25 2008 - 16:17:13 CDT

The answer to your question is TCL forces, where you can apply varying
forces that you could update at each step.

That tutorial might be useful for a start. Please note that this is a
constant velocity pulling at z-direction only. You might wanna modify your
force vector as you wish (using coordinates of the two particular atoms you
were mentioning).

Hope that'll help...

On Fri, Apr 25, 2008 at 4:23 PM, Yang Gao <> wrote:

> Dear all,
> I want to apply an restaint force between two atoms during NAMD run, just
> adding a external force in the line that connect the two atoms, but change
> nothing else. I have searched tutotials but just find in SMD how to define
> a
> constant velocity or force pulling in a fixed direction. But as the atoms
> may
> change their direction during runtime, this may not suitable for my case. I
> hope some of you may know the codes for define the specific interation or
> modify the SMD code to change the direction of the force during runtime.
> Thank you very much.
> Gao, Yang


This archive was generated by hypermail 2.1.6 : Wed Feb 29 2012 - 05:21:00 CST