Re: how to switch off hydrogen bonds in TIP4P/2005 water

From: Axel Kohlmeyer (akohlmey_at_gmail.com)
Date: Sat May 25 2019 - 12:50:45 CDT

On Fri, May 24, 2019 at 9:46 AM Monika Madhavi <monikamadhavi_at_gmail.com>
wrote:

> Dear all,
>
> I would like to mimic a situation where hydrogen bonds are not formed in
> water. So I want to simulate water but hydrogen bonds should not be formed
> (or should be weaker than normal). I would like to use TIP4P/2005 water
> model for this purpose. I have a parameter file for TIP4P/2005 water. Is
> there a standard way to switch off hydrogen bonds in TIP4P/2005 water?
>

hydrogen bonds are not an explicit term of the force field, but rather a
consequence of the specific geometry and charge distribution of molecules.
thus you cannot "turn them off".

If I reduce the charge on oxygen or reduce the charge difference between
> hydrogen and oxygen, will that do the job? Should I consider about cutoff
> distances also?
>

changing the charges changes the water model and the balance between the LJ
and the Coulomb interactions. you would be modeling a different species.

axel.

>
> Thank you.
> Best regards,
> Monika
>
> --
> W.A.Monika Madhavi
> Lecturer (Probation),
> Department of Physics,
> University of Colombo.
>

-- 
Dr. Axel Kohlmeyer  akohlmey_at_gmail.com  http://goo.gl/1wk0
College of Science & Technology, Temple University, Philadelphia PA, USA
International Centre for Theoretical Physics, Trieste. Italy.

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