Dielectric properties of I-III-VI2-type ternary chalcopyrite semiconductors, including linear and second order nonlinear optical susceptibilities at 10.6 mm, have been quantitatively studied from the chemical bond viewpoint. Contributions from each type of constituent chemical bond, i.e., I u VI and III u VI bonds, to the total linear and nonlinear optical properties of these compounds at 10.6 mm have been theoretically determined. The chemical bond method quantitatively expresses the trends in the dielectric properties of these compounds, which is helpful for carrying out modeling of their properties.

ZnS nanobelts have been synthesized by a simple thermal evaporation method in a N2 atmosphere containing a small amount of CO and H2 gases. The synthesized ZnS nanobelts have a width in the range of 40 to 120 nm, a thickness of 20 nm, and a length of several micrometers. The nanobelts are single crystals with a hexagonal wurtzite structure growing along the [001] direction. A vapor–solid process is proposed for the formation of such nanobelts. The as-prepared nanobelts shows two emission bands, around 450 and 600 nm.

On the basis of the bond valence model, an approach is established to determine the dopant occupancy in the lithium niobate (LN) crystallographic frame. The dopant location can be easily assigned by comparing the deviation of its normal and calculated valence states, when such a dopant is arbitrarily placed in both Li+ and Nb5+ sites, respectively. Further, the parameter Global Instability Index is used to characterize the structural instability of doped LN crystals. The dopant occupancy in the LN crystallographic frame and its interaction with the LN matrix are quantitatively understood by the structural stability. Calculated threshold values of various dopants are further obtained in the present work.