Band Structure and Electron–Electron Interaction in Samarium Monosulphide

The method of augmented plane wave (APW) is used to obtain the band structure of the SmS compound in the semiconductor and metal phases. The noncentral part of the Coulomb electron‐electron interaction is taken into account in the first order perturbation theory. In this case the radial part of the wave APW‐function is taken as a zero approximation function. A multiplet structure of the excited configuration f 5 d, which provides a good description of the X‐ray photoelectron spectrum and optical spectrum ϵ 2 (ω), is obtained. The configuration fd is calculated for the interpretation of the optical absorption spectrum of the samarium monosulfide metal phase.