[gmx-users] fudgeLJ?

[Berk Hess]

>From: "nicolas Dinter" <dinter at rc.m-kagaku.co.jp>
>Reply-To: Discussion list for GROMACS users <gmx-users at gromacs.org>
>To: <gmx-users at gromacs.org>
>Subject: [gmx-users] fudgeLJ?
>Date: Mon, 30 Aug 2004 15:33:34 +0900
>
>Dear Gromacs users,
>
>I tried to use the fudgeLJ and fudgeQQ command,
>I had to my itp file:
>[defaults]
>;nonbondtype	combrule	genpair	fudgeLJ	fudgeQQ
>1			1		yes		0.5		1
>
>but the LJ energies are the same than without adding this comand, when I
>change fudgeQQ the Coul14 energy is multiplied by the given coefficiant in
>the itp file.
>
>Is sobebody can explain me why with fudgeLJ=1 fudgeQQ=0.5 I have changes 
>and
>with fudgeLJ0.5 fudgeQQ=1 not.

I have already updated the manual for the next release on this point,
since it is not completely clear.
fudgeQQ always works, also when gen-pairs=no
fudgeLJ only has an effect on the generated pair parameters.
You did not tell which forcefield you are using, but I would guess
that it has all pairs listed explicitly in the pairtypes section in 
ff???nb.itp.
Then no pairs need to be generated, even if gen-pairs=yes.

Berk.

_________________________________________________________________
MSN Search, for accurate results! http://search.msn.nl