Geometrical, electronic and optical properties of seven types ZnO from first-principles calculation

We have used first-principles density-functional theory calculations to determine the structural, electronic and optical properties of four known ZnO phases (B1, Fm3 ¯ m), (B2, Pm3 ¯ m), (B3, F4 ¯ 3 m), (B4, P6 ₃mc) and three predicted phases of ZnO modification (GeP, I4mm), (5–5, P6 ₃/ mmc), (NiAs, P6 ₃/ mmc). The difference of data calculated by LDA and LDA + U has been compared. In addition, the calculated ground state energies and structural parameters of these phases are in consistent with the reported theoretical and experimental results. We have discussed the band structures, densities of states and chemical bonding of the seven types. Further, we have compared the calculated values of the dielectric function of the B4 phase with the experimental values. In addition, the optical constants of the seven types of ZnO have been calculated by LDA + U and LDA, respectively, the results obtained by the two methods are compared and analyzed.