group id

Dear lammps developers,

I need to make a group based on atoms’ ID , the IDs are not in a special order and the number of atoms are large. is there any way that group id command reads a file including the atom id?

Thank you.

The group command gives you many options for how
to specify what atoms are in the group, not just ID.
If none of those options do what you want, then you'd
have to augment the command with a new option.