leila leila... at
Tue Feb 18 19:49:56 UTC 2014

Dear Axel, 

I am doing Fist simulation with cp2k but I want to use the Gromos and 
OPLS/AA force filed parameters. Can I use your program gmx2gromos to 
convert gromacs files to the files that is readable for cp2k like in 
regtest-8 ?
One of my problem is that I have CH3 in my molecule and in gromos force 
filed partial charges for CH3 is 0 (as the united atom of the GROMOS 
forcefield) and It doesn't consider single H atoms,  but "includes" these H 
into the C atoms. That means that the CH3 group is just one LJ-bead in the 
GROMOS forcefield.
How I can implement this type of parameters in CP2K format?

Thanks very much and Kind Regards, 

On Wednesday, August 27, 2008 9:03:02 PM UTC+2, Axel wrote:
> On Aug 27, 11:47 am, Laino Teodoro <teodor... at> wrote: 
> > Ciao Ewald, 
> > 
> > gmx2gromos is not part of the cp2k distribution. Have no idea how those 
> > files where created (maybe one of the guy that did it will reply here 
> > with more informations). Anyway since you want to use GROMOS FF 
> calculations 
> gmx2gromos was started by me when i was still in bochum 
> with the intent to use gromacs tools to build OPLS/AA 
> topologies for qm/mm and then run them with CPMD, which 
> requires gromos format topology files. 
> > if you already have them you should not need any additional file or 
> > conversion. 
> > If you don't have them please refer to the GROMOS website.. 
> please note that the format in cp2k (and cpmd) corresponds to 
> the gromos 96 file format. a minimal and reverse engineered 
> description is also in the qm/mm section of the cpmd manual. 
> perhaps somebody near you has an old gromos documentation 
> collecting dust on a shelf. 
> > or to the GROMACS website (maybe there you will find also information 
> > how to convert the two formats one in the other). 
> nope. since the gromacs tpr file is binary, you need to use 
> gromacs library functions to access to contents and convert them 
> to gromos. reading the gromos documentation is the better way. 
> that being said, you don't need to write gromos format topologies 
> to use the gromos force field. you just need the parameters and a 
> topology file in a format that is readable by cp2k. 
> cheers, 
>    axel. 
> > 
> > Teo 
> > 
> > On 27 Aug 2008, at 17:36, Ewald Pauwels wrote: 
> > 
> > > I get the feeling that these files were somehow converted from gromacs 
> > > format. Is this program (or another conversion utility) available 
> > > somewhere? Or, alternatively, is it described how the G96 topology and 
> > > connectivity should be structured?

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