中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3798-3802.doi: 10.1088/1009-1963/16/12/040
徐 斌1, 易 林1, 成 泽1, 程正则2
Xu Bin(徐斌)a) Cheng Zheng--Ze(程正则)a)b)†, Yi Lin(易林)a), and Cheng Ze(成泽)a)
摘要: With the help of ab initio full-potential linearized augmented plane wave (FPLAPW) method, calculating the electronic structure and linear optical properties is carried out for $X$Cd$_{2}$(SO$_4$)$_{3}$ ($X=$Tl, Rb). The results show that Tl$_{2}$Cd$_{2}$(SO$_4$)$_{3}$ (TlCdS) has a larger band gap than Rb$_{2}$Cd$_{2}$(SO$_4$)$_{3}$ (RbCdS) and the energy bands for RbCdS are more dispersive than those of TlCdS. From their partial densities of states (PDOS), we have observed that the hybridization between S ionic 2p and O atomic 2p orbitals forms SO$_{4}$ ionic groups. The remarkable difference between RbCdS and TlCdS is, however, the degree of hybridization between cation (Tl and Rb) and its surrounding oxygen atoms. In the view of quantum chemistry, the strong p-d hybridization indicates the existence of their cation ionic bonds (Cd-O, Rb-O, and Tl-O). The calculations of TlCdS and RbCdS show their optical properties to be less anisotropic. Their anisotropies in the optical properties mainly occur in a low photon energy region of 5--16 eV.
中图分类号: (Other inorganic compounds)