Cylindrical/spherical cut

Hello everyone,

I have an aluminum slab equilibrated at 300K with an NVT. I want to model a nanoparticle and I am considering two cases. The first, in which I would like to get a spherical cut and the second one, in which I would like to make a cylindrical cut, both cuts, would be obtained from two identical slabs.
I was wondering if some of you had done this before and if there is some LAMMPS command I could use, or if there is some other method you may know of?
After the cuts are made, I will be adding a shell of alumina. I am trying to do something similar to what has been done in this paper (Page 3: Setup) :

I appreciate your input!

The region command can be used with delete_atoms to carve out a cylinder
or sphere of particles. Then you could dump them or write them
to a data file and input them into another simulation. E.g. as a nanoparticle.