[gmx-users] mix berger ff with opls

[Marc Ferdinand Lensink]

On Fri, Mar 12, 2010 at 10:06:53PM -0500, chris.neale at utoronto.ca wrote:
> 
> Note that the "Berger" lipids were in fact developed by many people
> and they have come to be named by only one of the contributors. The
> reference that I use for my 1/8 scaling of the LJ 1-4 is:
> 
> Lindahl, E., and O. Edholm. 2000. Mesoscopic undulations and
> thickness fluctuations in lipid bilayers from molecular dynamics
> simulations. Biophys. J. 79:426?433.
> 
> where they state in the methods:
> 
> "1,4 electrostatic inter-actions were reduced a factor of 2 and 1,4
> Lennard?Jones interactions a factor of 8."
> 
> I believe that this idea originated in a Jorgensen paper looking at
> bulk simulations of n-alkanes, but ashamedly I can't recall for sure
> at this moment. If you need it, I can look it up next week (let me
> know).

And since we're quoting; From: Langmuir 2009;25:5230
"Nonbonded parameters (sigma and epsilon) between OPLS/aa head group
 atom and Berger acyl chain 1-4 pairs are scaled by a factor 8 as
 recommended [opls]"

[opls] JACS 1988;110:1657.

cheers,
marc