Linear and second-order optical response of different GaN nanowires

By employing ab-initio method, we have investigated and analyze the calculation of linear and second-order optical response of four different GaN nanowires namely two atom linear wire, two atom zigzag wire, four atom square wire and six atom hexagonal wire. First we have analyzed the two atom linear wire for the convergence study with respect to k-point sampling. Then we have investigated the linear and second-order optical response of all considered configurations and predicted that the strongest absorption occurs for four atom square nanowire cross-section, which is also the stable structure for GaN nanowire as reported somewhere.