[lammps-users] wrong number of atoms in region cylinder

Dear LAMMPS’s user,
I am confused over the figures calculated by LAMMPS. I set the area of cylinder so that it creates ~13572 atoms but LAMMPS created 13170 atoms. What is wrong with codes? Here is my script and LAMMPS’s output:
script: -
atom_style granular
boundary p p fm
newton off
lattice fcc 1.145
region cyl cylinder z 0.0 0.0 6.0 0.0 30.0 units lattice
create_box 1 cyl
create_atoms 1 region cyl
.
.
fix 1 all nve/sphere
fix 2 all gravity 1.0 spherical 0.0 -180.0
fix 3 all wall/gran 200000.0 NULL 50.0 NULL 0.5 0 zplane 0.0 NULL
.
.
.
.
dump id all atom 100 dump.silo
run 25000

and output:

[ram@…436… today]$ mpirun -np 4 lmp_linux<in.silo
LAMMPS (7 Jul 2009)
Lattice spacing in x,y,z = 1.51735 1.51735 1.51735
Created orthogonal box = (-9.10408 -9.10408 0) to (9.10408 9.10408 45.5204)
1 by 1 by 4 processor grid
Created 13170 atoms
Setting up run …
Memory usage per processor = 9.81003 Mbytes
Step Atoms KinEng 1 Volume
0 13170 0 0 15091.703
.
.
Please can anybody explain about the area created by LAMMPS (bold in above) as I put the area of cylinder and but it looks as an area of box!!? And why it creates wrong number of particles?
Thanks…
Ram

The box is the bounding box around your cylinder. I already
answered your Q as to how LAMMPS fills the cylinder with atoms.

Steve