[gmx-users] CHARMM-->GROMACS

[Erik Lindahl]

Hi,

Eric has a point here; if you later want to contribute the code to 
Gromacs, please implement the routines by looking at the equations in 
published articles and not by looking at Charmm (or any other) 
copyrighted code.

As for parameters, check the license or ask the author. If they are 
available without usage restrictions (like OPLS or Amber) then it is 
quite OK to just write a perl script and translate it. This should 
apply to most forcefields, since journals usually require the 
scientific results to be available. The alternative is to implement 
them from scratch based on the data tables in published journals :-)

Still, a little bit of courtesy goes a long way; Bill Jorgensen and 
Julian Tirado-Rives were very helpful when I implemented OPLS/AA.

Cheers,

Erik