Regarding usage of pair_style kim in pair_style hybrid in lammps

Hello,

I want to use the pair_style kim in the pair_style hybrid command in lammps. I saw a post (OpenKIM · LAMMPS 'pair_style kim' command extended to support 'pair_style hybrid' and 'fix adapt' · Interatomic Potentials and Force Fields) which says that pair_style kim supports pair_style hybrid in lammps. However, I am still unable to use it in the latest version of lammps (showing pair_kim does not support hybrid). Please let me know what needs to be done in this case as I need to use pair_style hybrid for my simulation. Waiting for your kind reply.

Thanks and Regards
Sankalp

Hello Sankalp,

Thanks for you message and for using OpenKIM!

Unfortunately, I’m afraid it is not now possible to use the current version (2.X) of the KIM API with the pair_style hybrid in lammps. Version 1.X of the KIM API did support this (as you found from the OpenKIM news post you linked to), however in moving from 1.X to 2.X this feature became unavailable due to a basic design decision that was made to simplify application and use of the KIM API.

There are future plans (as part of a KIM API V3.0) to restore this feature, although there is currently no time-line for when that will happen.

I’m sorry I don’t have better news for your needs. Perhaps, if you want to start another thread and describe what you would like to do, we might be able to suggest an alternative solution.

Best,
Ryan

Hello Ryan,

Thank you for the reply. Is it still possible to use the version 1.X in lammps? In that case, it may still be very helpful for my case.

Regards
Sankalp

Hello Sankalp,

It is possible, but you’ll need to find an older version of lammps from the time when v1.X of KIM API was the current version.

Best,
Ryan