Can you please specify what exactly you mean by “weird?” What behavior do you expect from LAMMPS and how does it differ from what LAMMPS returns? If you are below jamming, are all particles just rattlers?
All particles will be rattlers if system is below jamming. For an already jammed system (a sample), when I calculate within the nonrattler group containing 99 particles, I would expect the “compute atom” command give me an array with len(array) == 99, instead of 100 (the total particle numbers).
Also, I tried to generate new packing samples, during which I can monitor the average pair force and average total force of all particles. As shown in my previous post, when the system is nearly jammed, “compute nonrattler” gives zero average total force and no pair force, but “compute all” yields reasonable results. So I think it is weird.
It is also generally hard to give any detailed advice without information on your specific system and input script. Some advice for posts can be found here. For instance, I don’t know what pair style you are using. There is a caveat for granular pair styles on the compute pair/local doc page which may or may not be relevant.
The simulation concerns frictionless granular particles interacting with hooke law, i.e.,
pair_style granular
pair_coeff * * hooke 1 ${gamma} damping mass_velocity limit_damping tangential linear_history 1 1 0
I have attached necessary files (one packing sample, one analysis script, and one packing-generation script, respectively). Thank you for your prompt response.
test.in (2.8 KB)
test.data (8.7 KB)
nph_mono.in (4.1 KB)