From: Ajasja Ljubetič (ajasja.ljubetic_at_gmail.com)
Date: Fri Oct 23 2015 - 03:28:28 CDT

Perhaps https://github.com/ParmEd/ParmEd. Will fit your needs.
I did not yet have a chance to try it out personally, but I plan to in the
near future.

Under "What it can do" it says:

Translate between a variety of file formats in common use by various
programs including:

   - Amber prmtop, inpcrd, NetCDF trajectory, and NetCDF restart files
   - CHARMM PSF, coordinate, and restart files
   - Gromacs topology and GRO files
   - PDB files, supporting a wide range of dialects that technically
   violate the PDB standard
   - PDBx/mmCIF files – the new standard for the Protein Data Bank

Best,
Ajasja

On 23 October 2015 at 09:34, Francesco Pietra <chiendarret_at_gmail.com> wrote:

> Hi:
> I am looking for a tool to convert gromacs topology (and possibly also
> params) to charmm. In my hands, psfgen (vmd in text mode with 43a1.rtp) is
> unable to read gromacs .rtf topologies.
>
>
> On the web I was able to find tools for charmm -> gromacs only.
>
> thanks for advice
>