Absolute determination of band structure E(k) by combined very-low-energy electron diffraction and photoemission

Very-low-energy electron diffraction (VLEED) is a direct probe for the unoc cupied electronic band structure E(k) corresponding to the upper bands of p hotoemission (PE). These bands can contain significant non-free-electron an d self-energy effects. Use of the experimental VLEED bands in PE and invers e PE allows to determine the valence and conduction hand E(k) absolutely, i .e. with complete and approximation-free control of the 3D wavevector k.