[lammps-users] region sphere


when i create a region sphere simulation box, using lattice units, i
wonder what a geometric region of space looks like on earth,how can i
calculate the number of the atoms? example: how many cubic lattice
box for the region 0,0,0 3 will be create?
p.s. in the potentials content what the differ is between the file
cuu3.eam and the file cuu6.eam