Oh, ok, I make some wrong copy.

It should the 'distribution of Voronoi index of certain type of atom'.

For example, my sample have A, B, C type atoms.

I want to find the distribution of polyhedron formed around A.

Since the above script is to find the distribution of polyhedron formed around A, B and C totally,

I have no idea on how to edit it.

Sorry for my confusing wording!