Ab initio calculations of exciton effects in optical spectra of an α-B{sub 12} crystal
- Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)
The dielectric functions and energy loss spectrum of electrons of a rhombohedral α-B{sub 12} crystal are studied both in the single-particle and many-particle approximations using Bethe–Salpeter equations. The opposite roles of different contributions to exciton effects are discussed. The anisotropy of dielectric functions is shown, which demonstrates their high sensitivity with respect to the three-dimensional packing of icosahedrons. The influence of the coherent mixing of electronic and exciton states on the redistribution of oscillator strengths is found. The position of the plasmon of valence electrons and the high-frequency permittivity are found to be consistent with experimental data. The correlation between the distribution of oscillator strengths and features of the density of electronic states is discussed.
- OSTI ID:
- 22756319
- Journal Information:
- Journal of Experimental and Theoretical Physics, Vol. 125, Issue 3; Other Information: Copyright (c) 2017 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evidence for anisotropic dielectric properties of monoclinic hafnia using valence electron energy-loss spectroscopy in high-resolution transmission electron microscopy and ab initio time-dependent density-functional theory
Ab-initio Calculations of Absorption Spectra of Semiconducting Nanowires Within Many Body Perturbation Theory