where s is a constant known as a screening constant, n * is an effective quantum number that is related
to n , and Y l,m ( θ , φ ) is a spherical harmonic that gives the angular dependence of the wave function. The
spherical harmonics are functions that depend on the values of l and m as indicated by the subscripts.
The quantity ( Z s ) is sometimes referred to as the effective nuclear charge, Z *. The screening con-
stant is calculated according to a set of rules that are based on the effectiveness of electrons in shells to
screen the electron being considered from the effect of the nucleus.