Density functional calculations of the reflectivity of shocked xenon with ionization based gap corrections

Experimental results [1] for the reflection coefficient of shock compressed xenon are compared with results from quantum molecular dynamics calculations with density functional theory (DFT). The real part of the optical conductivity is calculated within the Kubo-Greenwood formalism and the Kramers-Kronig relations are used to generate the reflectivity and other optical properties. Improved agreement over non-ideal plasma theory [2] is found with the DFT calculations, but significant differences with the data remain. Since DFT in the various local density approximations tends to underestimate the band gap and overestimate the free electron population, we have used the ionizations from [2] to correct the DFT band gaps. This results in much improved agreement with the xenon reflectivity data and demonstrates a new approach to correcting DFT band gaps. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim