Resonant Inelastic X-ray Scattering of Hexagonal Boron Nitride

We present resonant x-ray emission spectra, both measured and calculated, at the nitrogen edge of hexagonal boron nitride. Using the Bethe-Salpeter equation as implemented in the {\sc ocean} code, we investigate the effects of {\it GW} self-energy corrections and atomic disorder on the spectra. We highlight the importance of considering the effects of the core-hole excitation on the vibrational state of the system, and point to ways to include such effects in calculations of extended systems.