[lammps-users] 2d simulation with lammps.

Hi all.

Today i found strange requirement in lammps documentation:
http://lammps.sandia.gov/doc/Section_howto.html#4_2

Make the simulation box periodic in z via the boundary command. This is the default.
Is it nesessary to have periodic conditions over Z?
I suggest we have influence from virtual image of system.
I cheked potenrial energy of hex system, and it diferent from clear 2d system.

Has anyone had experience with 2d system in lammps?

If you use the dimension 2 command, there are no images in z.
Nearly all the input scripts in the examples dir are 2d. They
work fine in this mode.

Steve