Re: [AMBER] ff03 force field

From: <>
Date: Thu, 07 Jul 2011 17:08:07 -0400


I am trying to add extra points for CN- molecule. As suggested by you I am
studying the extra_pts.f code and trying to extend it. I have managed to
add a new frame type for CN. The problem that I am facing is that the code
needs three atoms for a frame (first neighbor, middle atom with EP, third
neighbor) .

CN has two EP at C, the problem is that I don't have a three atom frame.

I am thinking of putting a dummy coordinate for the third neighbor just as


I was wondering if you could suggest anything for my case, as I am getting
a lot of errors in my procedure of changing the code.

Surma Talapatra
Graduate Student
Geva Group
University of Michigan

On Wed, 06 Jul 2011 23:59:56 -0400, <> wrote:
> Thank You Dac.
> ~Surma
> On Sun, 3 Jul 2011 12:59:17 -0400, case <> wrote:
>> On Thu, Jun 30, 2011, wrote:
>>> Is it possible to add the extra point stuff in ff03 forcefield? Or, I
>>> have
>>> to use the polarizable force fields only.
>> This becomes a matter of semantics: if you add extra points to ff03, it
>> would
>> no longer be "ff03". But one could certainly have non-polarizable force
>> fields with extra points.
>> That said, it is not easy in Amber to devise new types of extra-point
>> force fields. You pretty much have to study and understand the code
>> implements extra points, then modify it to fit your needs.
>> ...dac
>> _______________________________________________
>> AMBER mailing list
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Received on Thu Jul 07 2011 - 14:30:03 PDT
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