THEORETICAL-STUDY OF ULTRAVIOLET PHOTOEMISSION SPECTRA OF TRANSITION-METAL DIHYDRIDES

We present the ab initio calculations of the ultraviolet photoemission spectra (UPS) of the early 3d transition metal dihydrides (TMDs). The calculations are based on the energy band structure calculated by the self-consistent linear augmented plane wave method (LAPW). The spectr a for ScH2 and TiH2 are compared with experiment. Significant discrepa ncies have been found between the theoretical and measured spectra. Fo r ScH2 the disagreement is most pronounced. To reveal the reasons for this, the spectra of the real and imaginary parts of the dielectric fu nction (DF) of ScH2 have also been calculated and compared with experi ment. Contrary to the UPS calculations, the DF calculations are in goo d agreement with experiment.