Spin–orbit splittings in the valence states of XH (X = K, Ca, Ga, Ge, As, Se, and Br) by the effective Hamiltonian approach

One advantage of the effective valence shell Hamiltonian method is that the spin–orbit coupling energies of all valence states, regardless of the number of valence electrons, are simultaneously determined with a similar accuracy from a single computation of the effective spin–orbit coupling operator. To assess the accuracy of the effective Hamiltonian method extensively, calculations are performed for the spin–orbit splittings in the valence states of fourth row diatomic monohydrides and their ions. The calculated spin–orbit splittings are generally in good agreement with known experiments or computations. Furthermore, the spin–orbit splittings of valence states, for which neither experiment nor theory is available, are predicted.