[lammps-users] How to Change the Number of atoms of the EXAMPLE suite (Crack Propagation)

Hi All
I am new to LAMMPS.
I installed LAMMPS( parallel) successfully.
Now I am using Crack propagation example.

I need long simulation ( ie each run should take 40 mins to 2 hrs).
SO I want to increse the Number of atoms ( without altering the number of steps).
Which parameter I have to change in crack.in file.
and Also want to know, how those parameters involved in calculation of number of atoms.

Thanx in advance

Sanjay

If you make the region bigger and fill it with
atoms, you'll get more of them.

Steve