First-principles study of the optical properties of BeO in its ambient and high-pressure phases.
Résumé
Optical properties such as the dynamic dielec. function, reflectance, and energy-loss function of beryllium oxide (BeO) in its ambient and high-pressure phases are reported for a wide energy range of 0-50 eV. The calcns. of optical properties employ first-principles methods based on all-electron d. functional theory together with sum over states and finite-field methods. Our results show subtle differences in the calcd. optical properties of the wurtzite, zincblende, rocksalt and CsCl phases of BeO, which may be attributed to the higher symmetry and packing d. of these phases. For the wurtzite phase, the calcd. band gap of 10.4 eV corresponds well with the exptl. value of 10.6 eV and the calcd. (av.) index of refraction of 1.70 shows excellent agreement with the exptl. value of 1.72. [on SciFinder(R)]