[lammps-users] granular particles of two different diameters

Dear LAMMPS users,

I want to put granular particles of same material type but of two different diameters ( 2mm and 4 mm) in cylinder using lattice units. Is it possible and how?
please anybody who can suggest to do that.
Sincerely yours,

If you're reading granular particles from a data file, then each particle
has its own diameter. They can be polydisperse. If you created
a bunch of particles (e.g. on a lattice), then you can use the
set command to change the diameter of some of them.