[gmx-users] TIP4P, TIP4P-Ew

[Tsjerk Wassenaar]

Hi Lin,

>From the amount of questions you pose on the user list and the
unfamiliarity you display with Gromacs/MD basics, it seems that you're
not as experienced with 1. MD, 2. Gromacs and 3. Force fields as you
should be when you modify parameters. That's an experienced-level
topic on which you can burn your fingers when you don't know what
you're doing. Learn to crawl, then learn to walk. Learn to walk, then
learn to run.

Cheers,

Tsjerk

On Sat, Sep 27, 2008 at 9:33 PM, Florian Dommert
<dommert at fias.uni-frankfurt.de> wrote:
> * Chih-Ying Lin <chihying2008 at gmail.com> [2008-09-27 11:20:07 -0700]:
>
>> Hi
>> There are several parameters to determine a TIP4P or TIP4P-Ew water.
>> r(OH), Å
>> HOH, deg
>> r(OM), Å
>> A × 10???3, kcal Å12/mol
>> B, kcal Å6/mol
>> q(M)
>> q(H)
>> dipole moment
>> .
>> .
>> .
>> etc....
>>
>>
>> But, from the tip4p.itp, I only found
>> r(OH), Å
>> HOH, deg
>> q(M)
>> q(H)
>>
>> where are the other parameters to put in?
>>
>> Thank you
>> Lin
>
> Hi Lin,
>
> just a small hint. If you want to adapt a Force Field or topology you
> have to very very careful. You have to chose the correct units,
> parameters and so on. This means you have to familiar with potentials
> used in Gromacs and the dependencies between the different parameters.
> The required information is contained in the manual but not in a bulk. It is
> distributed, so take some time go through the manual and I am sure you will
> find every information you require.
>
> Best Regards
>
> Flo
>
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>
> --
> Florian Dommert
> Dipl.-Phys.
>
> Computational and Theoretical Softmatter & Biophysics group
>
> Frankfurt Institute for Advanced Studies
> Johann-Wolfgang-Goethe University
>
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>
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-- 
Tsjerk A. Wassenaar, Ph.D.
Junior UD (post-doc)
Biomolecular NMR, Bijvoet Center
Utrecht University
Padualaan 8
3584 CH Utrecht
The Netherlands
P: +31-30-2539931
F: +31-30-2537623