Best way to convert LAMMPS ReaxFF file to CP2K-compatible file?

[sall...@ucr.edu]

Hi!

I'm new to CP2K (and to molecular dynamics in general). I would like to use the ReaxFF force field for an MD calculation in CP2K and would like to know the best (in terms of ease and efficiency) way to load the ReaxFF parameters. 

I have a LAMMPS file, which is attached, so I'm hoping there is a way to convert this to one of the CP2K file formats (AMBER, CHARMM, etc.). If not, I would also appreciate help with specifying them manually with keywords in the input file.

Thanks in advance!

Sarah

[Conrad]

Hi Sarah,

I don't think there's an easy way to "convert" ReaxFF to CHARMM or AMBER. They're not different file formats - they're totally different forcefields with different functional forms.

What's the motivation for this question? Is it only to get a classical forcefield running with CP2K for your system? I ask because ReaxFF is a reactive forcefield and quite a differt beast from the others you mentioned, and behaves very differently.

Best wishes,
Conrad

[Yingchun Zhang]

The implementation of ReaxFF is quite different from that of normal FF: the function forms and the calculation of bond order. And even the implementation in lammps is somehow independent from other FF, a USER-package and totally different input files.  

And another problem is that no 'REACTIVITY' remains once you converted ReaxFF to normal FF, which have bonded term.

Hope this help!