Shock Wave

Dear Lammps Users


I have a problem with fix wall/piston command of shock package:

I have two different types of atoms in the front of zlo (the piston face).
Simulation snapshots show that one type of atoms moves with the piston but the other type does not move.
As a group of atoms does not move, I think that the boundary condition of “s” does not allow the zlo of simulation box change and my simulation box size does not change.
Also, I have some fix recenter commands in the previous sections of my input script but using the unfix command I removed them.

Here is my commands for shock wave:

#----------------------------Piston Definition---------------------

change_box all boundary p p sf
fix 1 all nve
fix 2 all wall/piston zlo vel 0.0 0.0 2 temp 1 0.001 4223352 3 units box

#------------------------Shock Wave Loading-------------------------------------

timestep 0.0001
thermo 100
thermo_style custom step temp pzz
thermo_modify lost warn flush yes
run 34200

Any help is appreciated in advance.

Mahdi Tavakol

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