Electronic structures, spontaneous polarization, dynamical and nonlinear optical (NLO) properties of polar oxide ZnSnO(3) with LiNbO(3) (LN)-type structure have been investigated in the framework of density functional theory. By analyzing the Born effectives of LN-type ZnSnO(3), we find that Z* of Zn atoms show relatively large anomalous behavior. The spontaneous polarization is attributed to the large displacement of Zn atoms because of the mixed ionic-covalent character between the Zn-O bonds. The optical dielectric tensor is nearly the same; however the static dielectric tensor shows strongly anisotropy. Furthermore, the nonlinear optical properties are calculated by using 2n + 1 theorem applied to an electric-field dependent energy functional. The large dielectric constants and NLO susceptibilities indicate that the LN-type ZnSnO(3) would be a candidate as a high-performance dielectric and nonlinear optical material.

Using the full-potential linearized augmented plane wave method, we study the magnetism and electronic structures of C-doped ZnS (zinc-blende structure). Calculations indicate that C can induce stable ferromagnetic ground state in ZnS hosts. The magnetic moment of the 64-atom supercell (containing one CS defect) is 2.00μB. Low formation energy implies ZnS0.96 875C0.03 125 can be fabricated experimentally. Electronic structures show C-doped ZnS is p-type half-metallic ferromagnetic semiconductor and hole-mediated double exchange is responsible for the ferromagnetism. Relative shallow acceptor levels indicate C-doped ZnS is ionized easily at working temperatures. Several doped configurations calculations suggest ferromagnetic couplings exist between the doped carbon atoms.

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The full potential linearized augmented plane wave method together with the Tran-Blaha modified Becke-Johnson potential is utilized to investigate the electronic structures and magnetism for boron doped GaN and InN. Calculations show the boron substituting nitrogen (BN defects) could induce the GaN and InN to be half-metallic ferromagnets. The magnetic moments mainly come from the BN defects, and each BN defect would produce the 2.00 μB total magnetic moment. The electronic structures indicate the carriers-mediated double exchange interaction plays a crucial role in forming the ferromagnetism. Positive chemical pair interactions imply the BN defects would form the homogeneous distribution in GaN and InN matrix. Moderate formation energies suggest that GaN and InN with BN defects could be fabricated experimentally.