[gmx-users] Re: fudgeLJ and fudgeQQ setting in the *.itp file

[Vitaly Chaban]

Dear Amir:

Generally your intuition is the only reason. For the standard FFs
these values are given being 0.5, 0.83, 1... Only if you try to fit
the potential energy surface, the motives of these numbers usage are
clearer.

Dr. Vitaly Chaban


>
> Hi All,
>
> I was just wondering whether someone knows what are the considerations in
> choosing the values for* fudgeLJ* and *fudgeQQ* in the [defaults] section of
> the *.itp file. (these  two  factors multiply the 1-4 LJ interactions and
> the electrostatic interactions , respectively)
>
> the manual doesn't say much but using defaults of 1.0, but I wanted to know
> whether one should change those and if so, on what cases?
>
> Many Thanks,
> Amir