Infrared and Raman spectra of $\ensuremath{\beta}\text{\ensuremath{-}}\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ from first principles calculations

Infrared and Raman spectra of $β − B C_{2} N$ from first principles calculations

Jian Sun, Xiang-Feng Zhou, Jing Chen, Ya-Xian Fan, Hui-Tian Wang, Xiaoju Guo, Julong He, and Yongjun Tian

Phys. Rev. B 74, 193101 – Published 1 November 2006

Abstract

We present the study on the infrared and nonresonant Raman spectra of $β − B C_{2} N$ within the framework of ab initio pseudopotential density functional perturbation theory in a four-atom orthorhombic unit cell. The Raman tensors are calculated from the second-order response of the electronic density matrix with respect to a uniform electric field. Comparison between experiments and calculations for cubic BN is presented to test our method in reproducing all the measured features quantitatively. The LO/TO splitting is well imposed by adding the nonanalytical part deduced from the Born effective charge and macroscopic dielectric constant. Finally, different Raman experiment configurations for $β − B C_{2} N$ are discussed.