Re: varying two colvar distances simultaneously

From: Giacomo Fiorin (
Date: Thu Mar 24 2016 - 16:53:46 CDT

Hello Chitrak, you could define a variable as the difference between two
distances (there is an example in the manual) and restrain the difference
near zero.

Note that an exact equality will not be possible, because that would
require a constraint solver.

On Thu, Mar 24, 2016 at 5:49 PM, Chitrak Gupta <> wrote:

> Hello!
> I am newly using the colvars module. Is there a way to vary two different
> colvars distance in a way that they are always equal to each other?
> Basically, I want to vary two distances simultaneously, resulting in only
> one dimension. Is that possible?
> Regards,
> Chitrak.

Giacomo Fiorin
Assistant Professor of Research
Institute for Computational Molecular Science (ICMS)
College of Science and Technology, Temple University
1925 North 12th Street (035-07), Room 704D
Philadelphia, PA 19122-1801
Phone: +1-215-204-4213
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*"As computer programmers we have a responsibility to make sure that we run
the computers instead of the computers running us."*  - Steve Oualline

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