[gmx-users] Re: mathematical expression to obtain the C6 and C12 LJ terms for the GROMOSXX ff family

[Mark Abraham]

On 29/03/2011 12:17 AM, sa wrote:
>
>     OK, Pr van der Spoel,
>
>
> So what is the correct way to obtain LJ C6 and C12 values given in the 
> [ atomtypes ] and in the [ nonbond_types] sections of ffnonbonded.itp 
> if I have only the sigma and epsilon values.
>
> If understand well [ atomtypes ] section give the comb-rules for the 
> atom with itself, correct ? And the nonbond_types section, the 
> comb-rules with the other atoms types.
>
> So if  I take into account only the OM atom, as an example, why I 
> obtained different values for C6 and C12 terms in the [ atomtypes ] 
> section.
>
> Thank you again for your help.

Section 5.3.3 of the manual goes through this.

Mark
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