Dear LAMMPS Users,

The number of atoms changes with the same input except different scales(denoted as a) in the lattice command.

dimension 3

units metal

boundary s s p

atom_style atomic

lattice fcc $a origin 0 0 0 orient x 1 1 -2 orient y 1 1 1 orient z 1 -1 0

region box block 0 3 0 1 0 3

create_box 1 box

create_atoms 1 box

if a=1,2,3,...or 3.625,3.635,3.675, the number is 192;

if a=3.615(lattice constant for Cu),3.665, the number is 190;

if a=3.605,3.645,3.655,3.695, the number is 191.

why are some atoms lost for some scale values?

Thank you for your time. Any help is appreciated.

Zhenhai Xu