Coulomb (or Strong) Correlation Effects in the Band Structure of Eu2O3

Two band‐structure calculations of Eu2O3 are performed, one of them in the metallic phase and the other in the semiconducting phase; the difference between the corresponding band Hamiltonians is the occupation potential U (r) that includes the Coulomb correlation effects. In both phases, the 4f occupied bands are mixed with the 2p bands; this fact broadens these 4f bands so that its calculation is possible in this complex crystal lattice T . In the semiconducting band structure, the 4f empty bands are localized in the d‐zone energy showing (4f, 5d) hybridization that produces a broadening still greater than for the 4f occupied bands. The semiconducting gap is Γ – H and its value is 3.7 eV.