Future Trends in Modeling Electron Energy Loss Near-Edge Structure (ELNES)

Abstract The increasing availability of fast, multiprocessor high performance computing facilities has revolutionized iterative electronic structure calculations of solids, particularly for those systems possessing little or no symmetry. This combined with the semi-commercial dissemination of well-supported software packages for the calculation of both occupied and unoccupied electronic states at high levels of approximation has opened up the possibilities for more routine modeling and understanding of electron energy loss near-edge structure (ELNES) data obtained in the TEM/STEM, and hence the elucidation of chemical bonding in solids at high spatial resolution. The two modeling approaches presented and compared here involve ab-initio band structure calculations based on the full linear augmented plane wave (FLAPW - WIEN97) approach, and full multiple scattering (MS) clusterbased methods. We have performed a systematic study of transition metal carbides and nitrides and compared the modeling results with high resolution EELS data.