Error while calling an openkim model from lammps

Dear Openkim users,

I am using lammps’ python interface to call an openkim model, using the following commands,

lmp.command(“pair style kim KIMvirial model_Ar_P_Mors”)
lmp.command(“pair_coeff * * Ar Ar”)

as detailed in the link,

However, I am getting the following errors, (with openkim installed),

ERROR: Unknown command: pair style kim KIMvirial model_Ar_P_Mors (…/input.cpp:313)

Could you suggest a way around to fix it?



Hi Swayam,

It looks like you just forgot the underscore in 'pair_style'.


Also you dropped the ending 'e' in model_Ar_P_Morse


Hi, thanks. Corrected it. I still get an error though saying, ERROR: Unknown pair style (…/force.cpp:183). Is it due to the reason that it’s not able to find the model_Ar_P_Morse?

This sounds like you have not compiled lammps with kim support. You need to do something like "make yes-kim" as part of the lammps build process.


Hi, thanks a lot for the info.

Hi Ryan, hope you are well. I have built lammps with kim support.

However, I get the error saying,

ERROR: Incorrect args for pair coefficients (…/pair_kim.cpp:336)

Is there a way to fix it?