[gmx-users] criticism invited...

[Anton Feenstra]

Christoph Freudenberger wrote:
> Paul Barrett wrote:
> 
>> My (alledged) solution: combine this hydrogen with its neighbouring
>> oxygen by:
[...]
> I cannot judge how much this will effect the results in your special case,
> but i don't think it's "good force field practice".

I would tend to agree with that.

> I would try to add the hydrogens mass into the oxygen
> and define the hydrogen as a dummy keeping it's charge
> and LJ's.

Can't have a rotatable dummy, though. Try the addition of
a dihedral angle potential David suggested, and/or shift
mass from the oxygen to the hydrogen.

Do you get this spinning OH group repeatedly? If it only
happens eveery once in a while, you can use my 'upstream
tweaking': write a .trr frame in slightly reduced precision
(e.g. 6 in stead of 7 decimal places), and continue the
run with that. I;ve posted a more complete description on
the list only several days back.


-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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| \_/ \_/ | | | Tel: +31 20 44 47608 - Fax: +31 20 44 47610           |
|             | Feenstra at chem.vu.nl - www.chem.vu.nl/~feenstra/       |
|             | "If You See Me Getting High, Knock Me Down"           |
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