[gmx-users] 3.1.4 is out

[Erik Lindahl]

Hi,

I just put release 3.1.4 on the gromacs.org site; apart from a couple of 
fixes and improvements it includes the OPLS all-atom forcefield.

Since I had to modify a couple of formats to implement OPLS you will 
need 3.1.4 or later to use it. If you want to do free energy 
integrations with OPLS you might even have to use the CVS HEAD branch 
since it required a new tpr version to enable free energy for 
Ryckaert-Bellemans dihedrals.

OPLS-AA/L is probably the best forcefield available today when it comes 
to protein simulations; it consistently produces more accurate energies 
than any other forcefield. Hopefully there aren't any typos, but do let
us know if you find any errors or bugs.

For the moment, the OPLS residue database only contains aminoacid 
residues, but there are atomtypes for a wide selection of molecules 
(about 700 to be exact :-). The advantage with this approach is that you
normally don't have to derive new charges for a molecule; just build
a residue entry for the .rtp file and you're set.

Cheers,

Erik