how to group atoms introduce randomly with create_atoms?

LAMMPS LAMMPS Mailing List Mirror
1

Dear LAMMPS users,

Inside a Fe bcc crystal I have introduced randomly some additional atoms the following way:

create_atoms 1 random 5000 6538 crystalFe

Now I would like to set their velocity (all the same). This can be done with the command velocity group-id set v_x v_y v_z.

The question is how to group the atoms that I have introduced randomly. Any idea?

Many thanks in advance and best regards,
Christophe

2

There are several methods to achieve that:

  1. Set another type to the additional atoms (group group-id type X).
  2. Create the atoms at the beginning (group group-id id > 0).
  3. Use IDs of atoms (group group-id id > X).

Michal

3

There are several methods to achieve that:

  1. Set another type to the additional atoms (group group-id type X).
  2. Create the atoms at the beginning (group group-id id > 0).
  3. Use IDs of atoms (group group-id id > X).

This last one is just what I needed. It works fine. Thanks a lot!

Christophe