Re: [AMBER] angle restraint with atom groups

From: David A Case <>
Date: Mon, 30 Dec 2013 13:58:39 -0500

On Tue, Dec 31, 2013, Sourav Purohit wrote:

> Is it possible to define angle restraints using atom groups.

I believe this is possible in sander but not pmemd.

> If I choose to define angle restraint using three atoms, then how is the
> angle defined?? Is it the angle between the vectors corresponding to
> (iat1-iat2) and (iat2-iat3) or (iat1-iat2) and (iat3-iat2).

The latter; it would be what you would get for an angle defined by three
single atoms iat1, iat2 and iat3. But be sure to run some simple tests with
known geometries, to make sure you are getting the restraint you want.


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Received on Mon Dec 30 2013 - 11:00:03 PST
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