Session Z13 - Metals/Spectroscopy/Structure.
ORAL session, Friday morning, March 16
Room 206, Washington State Convention Center
We report calculations of the spectrum of electron-hole excitations in post-transition metal Zn, performed within the framework of time-dependent density-functional theory. A density-response calculation based on the use of the local-density approximation (LDA) is unable to account for the remarkable loss lineshape observed in recent electron energy-loss spectroscopy measurements. This failure of the LDA is, to a large extent, related to the energy location of the d-band threshold (spurious self-interaction). We performed additional self-consistent response calculations on the basis of a band structure obtained by invoking Slater’s Xa approximation. The loss function obtained for an “optimal” choice of the parameter reproduces the measured spectrum quite well. We provide a new interpretation of the measured line shape; this picture provides a consistent interpretation of the wave vector dependence of the oscillator strength of the d-electron onset.(*) Supported by NSF and NERSC. (**) Managed by UT-Battelle for the U.S. DOE under contract DE-AC05-00OR22725.