Electronic structure and optical properties of Ca(NH < inf > 2 < /inf > BH < inf > 3 < /inf > ) < inf > 2 < /inf > studied from GW calculations

Abstract

The quasiparticle band structure and optical properties of calcium amidoborane Ca(NH2BH3)2 have been studied by means of the GW approximation based on the projected augmented wave(PAW) method. From the calculated band structure, Ca(NH2BH3) 2 is found to be an insulator with a bandgap of 3.27 eV within GGA and 6.12 eV within the GW approximation. The dielectric function corrected by a scissor shift operation corresponding to the GW correction on the GGA bandgap is computed to obtain the optical properties. The different peaks in the optical spectra are studied in terms of optical transitions within the calculated band structure. The optical anisotropy of this material is analyzed through refractive indices and the static dielectric constants along the three principle axes. It is found that Ca(NH2BH3)2 system is optically less anisotropic than NH3BH3 due to similarities in the bonding along the a and c axes. © 2011 American Chemical Society.