Error when using airebo style

I am doing tutorial on breaking nanotube from here
using the following code:

variable T equal 300

units metal

atom_style molecular

boundary p p p

pair_style airebo 2.5 1 1


pair_coeff * * CH.airebo C

I get the following mistake

ERROR: Incorrect args for pair coefficients (src/MANYBODY/pair_airebo.cpp:183)
Last command: pair_coeff 1 1 0.066047 3.4

for some reason LAMMPS does not recoginze that I have correctly used * * (line 183 in .cpp file corresponds to the condition that first two arguments should be * and *)

surprisingly when i try something like

pair_coeff * * CH.airebo abracadabra

it recognizes that * * were used correctly and outputs another error regarding “abracadabra”

Please help, I wasn’t able to find any topics with similar mistake

both files CH.airebo and that I used seem perfectly fine


I tried running your input file with the following (slightly edited from the website you gave) and it works:

2 atoms
1 atom types
-40.000000 40.000000  xlo xhi
-40.000000 40.000000  ylo yhi
-12.130411 67.869589  zlo zhi


1 12.010700 # CA

Atoms # molecular

1 1 1 5.162323 0.464617 8.843235 # CA CNT
2 2 1 4.852682 1.821242 9.111212 # CA CNT

Suggestions I can think of to probably resolve your issue:

  1. make sure you have a sufficiently new LAMMPS version (I tested on 15 Jun 2023, the currently newest one is 2 Aug 2023);
  2. make sure that your input file only have 1 atom types;
  3. make sure your CH.airebo potential file is not broken (LAMMPS has it bundled in the installation).
1 Like

Thank you very much for taking your time and checking it out.
After a break I was able to find the issue.
I accidentally added external parameters file

include parm.lammps

substantially later in the file, which caused the issue.

It was a rather stupid mistake, which, however, stalled me for quite a while.