Atoms of different chemical elements have different numbers of protons in their nuclei. Because these protons attract the electrons, the strength of the electrons’ interaction with the nucleus varies for different elements. In terms of potential energy diagrams, the depth (in energy) and width of the potential well depends on the chemical element of the atom being considered.
By changing the potential energy diagram you can simulate the effect of a different sized nucleus. Use the parameters button. You can also use potentials of their shapes. Use the Potential pull-down menu item. Try different potentials to see how the solutions change. The numerical method can be used for any potential energy. However, rapidly changing potential may not work for some methods of finding numerical solutions.