# Creates an "NaCl like" structure in data.lmp file
# Assigns a type 2 to the second atom of a bcc lattice
# replicate the box in every direction 5x5x5=250 atoms
units metal
boundary p p p
atom_style atomic

lattice bcc 5.4
region Myreg block 0 1 0 1 0 1 units lattice

create_box 2 Myreg
create_atoms 1 box

set atom 2 type 2

mass * 1.

replicate 5 5 5

write_data data.lmp