Wannier-function description of the electronic polarization and infrared absorption of high-pressure hydrogen
arXiv:cond-mat/0007444 · doi:10.1103/PhysRevB.62.15505
Abstract
We have constructed maximally-localized Wannier functions for prototype structures of solid molecular hydrogen under pressure, starting from LDA and tight-binding Bloch wave functions. Each occupied Wannier function can be associated with two paired protons, defining a ``Wannier molecule''. The sum of the dipole moments of these ``molecules'' always gives the correct macroscopic polarization, even under strong compression, when the overlap between nearby Wannier functions becomes significant. We find that at megabar pressures the contributions to the dipoles arising from the overlapping tails of the Wannier functions is very large. The strong vibron infrared absorption experimentally observed in phase III, above ~ 150 GPa, is analyzed in terms of the vibron-induced fluctuations of the Wannier dipoles. We decompose these fluctuations into ``static'' and ``dynamical'' contributions, and find that at such high densities the latter term, which increases much more steeply with pressure, is dominant.
17 pages, two-column style with 14 postscript figures embedded. Uses REVTEX and epsf macros
References in corpus (9)
- Maximally-localized generalized Wannier functions for composite energy bands
- The physics of dynamical atomic charges: the case of ABO3 compounds
- Electron Localization in the Insulating State
- Polarization and localization in insulators: generating function approach
- Quantum and Classical Orientational Ordering in Solid Hydrogen
- Dipole-quadrupole interactions and the nature of phase III of compressed hydrogen
- Insulator-metal transition in solid hydrogen: Implication of electronic structure calculations for recent experiments
- Semiconductor effective charges from tight-binding theory
- Polarization and Strong Infra-Red Activity in Compressed Solid Hydrogen