[lammps-users] Hybrid and granular

Dear All,

We would insert a force (e.g. harmonic) between two particles in granular style. Since there is no force between the particles when r > d, I think we should use hybrid pair_style according to the manual of lammps:
“If a granular potential is used as a sub-style of pair_style hybrid, then specific atom types can be used in the pair_coeff command to determine which atoms interact via a granular potential.”

But as you know, the bond style uses point particles but granular does not, and I do not know how we can assign masses to particles in data file.

Is there any sample file for using granular style by hybrid command?

Any comment is appreciated!

Kind regards,

What pair style are you planning to use with granular that will
provide a harmonic attractive force? The doc page for
read_data describes the format of an atom_style granular
data file with per-atom masses.


Dear Steve,

We would add Hookean harmonic attractive interaction (for r>d) between some of granular particles. We thought that we can use “pair_style hybrid” to have both granular and harmonic bond interactions, but then I recognized that harmonic interaction is categorized in “bond_style” command (sorry, I mentioned pair style in my first email). Thus I think we could not use “hybrid” argument neither in bond_style nor in pair_style to achieve our goal.

What do you suggest us?

Many thanks.
Kind regards,