FULL-POTENTIAL PHOTOEMISSION CALCULATIONS FOR KTAO3

We have calculated the electronic structure of cubic KTaO3 using the s elf-consistent tight-binding linear muffin-tin orbital method (TB-LMTO ) as well as the full-potential linear muffin-tin orbital method (FP-L MTO). Due to the generalization of the one-step model of photoemission to the cast of several atoms per unit cell and the development of the full-potential photoemission theory, a detailed study of angle-resolv ed ultraviolet photoemission (ARUPS) intensities is possible now. Ther efore, we present calculated photoemission spectra from the (100) surf ace of a KTaO3 crystal in the cubic phase by excitation with unpolariz ed NeI and He I radiation. The results include a comparison of theoret ical data calculated from TB-LMTO and FP-LMTO potentials with recently measured experimental spectra. The overall agreement between theory a nd experiment turns out to be very satisfactory.