data file for RDX

I know that the data.RDX file in Lammps Examples directory contains just 105 atoms.
I will be very thankful if somebody helps me about that how can create a file for a crystal with two two-dimensionally periodic slabs containing a total of 1344 atoms (as reported in this paper by Van Duin:

There are few builder tools included in the LAMMPS
distro in the tools dir. You can also check this page

for other existing builder tools.