The nature of the first excited electronic state in BeF

Matrix Hartree-Fock wave functions are calculated for the 2 Σ + ground state and excited 2 II levels of BeF. The calculations indicate that the first excited 2 II state is derived largely from a configuration... 1π 4 2π but that a small contribution of the configuration... 1π 3 5δ 2 results in the spin-orbit coupling constant having a small negative value, the state thus appearing inverted.