Two‐dimensional fully numerical solutions of molecular Schrödinger equations. I. One‐electron molecules

A two‐dimensional fully numerical relaxation approach is presented for the electronic Schrödinger equation of linear molecules. The method is tested on the lowest σ, π, δ, and ϕ states of H and HeH 2+ . About 10‐figure accuracy is obtained for the orbital energies. Seven‐point numerical formulas are given for first and second derivatives.