Ab initio calculation of thermodynamic, transport, and optical properties of CH2 plastics

This work covers an ab initio calculation of thermodynamic, transport, and optical properties of plastics of the effective composition CH2 at density 0.954 g/cm(3) in the temperature range from 5 kK up to 100 kK. The calculation is based on the quantum molecular dynamics, density functional theory, and the Kubo-Greenwood formula. The temperature dependence of the static electrical conductivity sigma(1DC)(T) has a step-like shape: sigma(1DC)(T) grows rapidly for 5 kK <= T <= 10 kK and is almost constant for 20 kK <= T <= 60 kK. The additional analysis based on the investigation of the electron density of states (DOS) is performed. The rapid growth of sigma(1DC) (T) at 5 kK <= T <= 10 kK is connected with the increase of DOS at the electron energy equal to the chemical potential epsilon= mu. The frequency dependence of the dynamic electrical conductivity sigma(1)(x) at 5 kK has the distinct non-Drude shape with the peak at omega approximate to 10 eV. This behavior of sigma(1)(x) was explained by the dip at the electron DOS. (C) 2015 AIP Publishing LLC.