[gmx-users] Use of non-standard CHARMM27 forcefield in Gromacs - how?

[Jernej Zidar]

Dear all,
 During my PHD studies we developed a specific lipid force field
based on the CHARMM27 force field containing spingomyelin molecules of
various saturation and chain lengths.

 Now I would like to use this forcefield in Gromacs but I don't know
where to start. Is there a way to import it into Gromacs? The files
used in the Charmm simulations were:
top_all27_lipid.rtf
par_all27_lipid.rtf
toppar_all27_lipid_cholesterol.str (the one containing the specific
sphingomyelin bits)

Thank you in advance for any tip or suggestion,
Jernej Zidar