Structural, elastic, electronic and optical properties of black phosphorus, TiP and VP; ab initio study

Fig. 7. Optical spectra of P-Cmca for directions of the electric field (E), parallel (E//c) and perpendicular (E┴c) to the crystallographic c axes. Calculated reel [imaginary] parts of the dielectric function ɛ1(ω) [ɛ2(ω)], reel [imaginary] parts of the conductivity σ1(ω) [σ2(ω)] and refractive index n(ω) [extinction coefficient k(ω)] versus energy.135