Electronic Band Structure of YbInCu4and LuInCu4

Abstract

One-electron energy band structure for LuInCu 4 , which is a proper reference material for the study of the valence transition in YbInCu 4 , is calculated by a self-consistent APW method with the local density approximation. The calculated result shows that the compound is the semimetal. This property is consistent with the observed unusual behavior. In order to estimate the mixing term between the 4 f electron and the valence and conduction electrons, the energy band structure for YbInCu 4 is also calculated. The obtained result is followings; ( p f σ)=0.27 eV for Yb 4 f and Cu p states and ( d f σ)=-0.14 eV for Lu 4 f and Cu 3 d states. These values are nearly same order as those of Ce compounds.