Valence atomic orbitals on neighboring atoms combine to form bonding, non-bonding and antibonding molecular orbitals. In Section 1 the Schrödinger equation for the motion of a single electron moving about a nucleus of charge Z was explicitly solved. The energies of these orbitals relative to an electron infinitely far from the nucleus with zero kinetic energy were found to depend strongly on Z and on the principal quantum number n, as were the radial "sizes" of these hydrogenic orbitals. Closed analytical expressions for the \(r\),\(θ\), and \(ϕ\) dependence of these orbitals are given in Appendix B. The reader is advised to also review this material before undertaking study of this section.