The electronic structure of two V-based ladder compounds, the quarter-filled NaV2O5 in the symmetric phase and the iso-structural half-filled CaV2O5 is investigated by ab initio calculations. Based on the bandstructure we determine the dielectric tensor ϵ(ω) of these systems in a wide energy range. The frequencies and eigenvectors of the fully symmetric Ag phonon modes and the corresponding electron-phonon and spin-phonon coupling parameters are also calculated from first-principles. We determine the Raman scattering intensities of the Ag phonon modes as a function of polarization and frequency of the exciting light. All results, i.e. shape and magnitude of the dielectric function, phonon frequencies and Raman intensities show very good agreement with available experimental data.
@article{arxiv.cond-mat/0404076,
title = {Optical properties, electron-phonon coupling, and Raman scattering of vanadium ladder compounds},
author = {J. Spitaler and E. Ya. Sherman and H. G. Evertz and C. Ambrosch-Draxl},
journal= {arXiv preprint arXiv:cond-mat/0404076},
year = {2009}
}