[gmx-users] itp file using Gromos96 parameters

[Anton Feenstra]

Alan Wilter Sousa da Silva wrote:
> 
> I can figure out that if I include new ga_?? parameters in the
> ffG43a1bon.itp file I could get to complete my itp drug file.

Correct.

> Nevertheless, would GMX understand if I explicit the parameters in the
> drug itp file, like that?
> 
> [ angles ]
> ;    ai     aj     ak  funct  ang.  const.
>       1      5      4     2  110.0   100.0
>       2      6      7     2  ga_12 ;  C -  CH2 -   OA   110.0  109.5
>       6      7      8     2  ga_11 ;CH2 -   OA -    C    95.0  109.5
>       7      8      9     2  112.0   120.0
> 
> or I'd have change funct from 2 to 1 and so to explicit my parameters.
> Would GMX still respect Gromos96 force field?

Yes, GMX (grompp in this case) will not see a difference between the
ga_?? defines and explicit parameters. You can choose wheter to use
angle type 1 or 2, but 2 would be consistent with the Gromos96 (43a1)
forcefield. Gromacs will still use all the parameters as defined in
the Gromos96 forcefield for all interactions that you don't change
explicitly.

-- 
Groetjes,

Anton
 ________ ___________________________________________________________
|        | Anton Feenstra                                            |
| .      | Dept. of Pharmacochemistry - Free University Amsterdam    |
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