Core-hole effects on the B K edge in MgB₂

The projected density of states (DOS) for the ground and excited states of boron in MgB₂ has been calculated using the augmented plane wave plus local orbital method. The core-hole interaction is found to have a significant effect on the B p_xp_y states, but has little effect on the more metallic B p_z states. The unoccupied B p_xp_y DOS near the Fermi level decreases as a function of core-hole strength. Comparisons with experimental electron energy loss spectra of the B K edge show that a simulation with half a core hole provides the best approximation to the final states in MgB₂.