Summary: smaller nuclei have relatively more nucleons on the surface (these are not bound by neighbours on all sides), and larger nuclei have a stronger Coulomb repulsion. There has to be a maximum somewhere, and this happens to be at iron.
I am new to XPS Data analysis, and I have a .sle file that I got out of XPS Machine Software, and I am using CasaXPS to analyse the data. This software takes only .vms files. I want to convert the .sle to a .vms file for analysis. How or where can I do this? Any help on this will be deeply appreciated.