Sound wave in granular

Dear Lammps Developers,

I want to generate a wall or region made up of particles 1 that are above the second wall and dump particles 2 on the second wall.
I have created and defined the particles inside the region “wall2” and freeze them so that there is no movement between them, but when I run it I get an error.
Is this a wrong way to create a particle wall? How should I correct the code?
(The lammps I downloaded are LAMMPS-64bit-23Jun2022-update4-MPI.exe)
Here is my code,I’ll be gratefu for any suggestions.

abc9.lmp (2.8 KB)


What is the error message? Most error messages should be self-explanatory. From a quick glance it looks like you don’t define a lattice: lattice command — LAMMPS documentation

Thanks for your reply,
I have tried lattice before create_atoms, but there is another error: “Set command with no atoms existing”. So I deleted it.

This simply means no atoms exist when you call the set command. So you may need to rethink the set command’s group or location in the input script or maybe adjust the size of your region/lattice to ensure atoms are created. I would recommend starting with a small input script that just creates atoms, confirm it works, then gradually add more commands while addressing errors when they pop up.

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thanks again, I did it!!