A simple tight-binding theory with spin-orbit coupling for the analysis of two-dimensional band structures of adsorbates

A Slater—Koster-type simplified tight-binding theory is applied to the analysis of electronic states of ordered adlayers on single-crystal surfaces. The effect of spin—orbit coupling is introduced by using Pauli spinors. The Hamiltonian matrix including the spin—orbit terms takes a simple form, which enables us to reproduce and explain relatively easily angle-resolved UPS data for such systems. Examples of application to Te on Al(111) and Xe, Kr, Ar on Pd(100) are given.