[gmx-users] Re: Force Field Parameters Nitrogen and Oxygen

[Vitaly Chaban]

> Date: Tue, 12 Aug 2008 16:36:16 -0500
> From: "Andy Shelley" <robert.shelley at gmail.com>
> Subject: [gmx-users] Force Field Parameters Nitrogen and Oxygen
> To: gmx-users at gromacs.org
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>        <e398c2690808121436p7289e2bbvd498f07cabaaea16 at mail.gmail.com>
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>
> I am trying to simulate air and have not been able to find force field
> parameters for a Nitrogen Nitrogen bond or Oxygen Oxygen bond.  If you could
> please direct me to where these could be found I would appreciate it.
>
> Thanks,
> Andy

There is a multitude of ways to deal with your system. It's very pity
you don't say us what you want to simulate exactly.

I think even if you use rigid O-O and N-N molecules it will not affect
the results of your simulation in most cases. Of course, it depends on
which properties you want to calculate exactly.

If you are about to simulate not air (telling the truth, it's not an
up-to-date task) but something  in the air atmosphere, you may want to
use a 1-atom model for each gas component. Although I'm sure proper N2
and O2 models can be easily found in literature.

The force bond constants are in fact similar enough to one another and
you may point out a constant for an atom pair resembling yours.
However, I cannot suggest you this way as absolutely correct one.

-- 
Vitaly V. Chaban
School of Chemistry
National University of Kharkiv
Svoboda sq., 4, Kharkiv 61077, Ukraine
email: chaban at univer.kharkov.ua
skype: vvchaban