Computational Studies on Functionalized ZnO Surfaces and Nanostructures ZnO Functionalization Nanostructures Surface Chemistry DFT SCC DFTB. In this work we have used computer simulations to investigate the effect of organic functionalization on ZnO surfaces and nanostructures. Density Functional Theory has been employed to study the interactions of ZnO surfaces with different organic groups identifying stabilization mechanisms involved in each case and the most promising anchoring groups for ZnO functionalization. Additionally a semi empirical model for ZnO large scale simulations has been developed and validated by comparison against DFT calculations. The was successful in simulating Zn containing bulk solids and molecular complexes ZnO surfaces and nanostructures and the adsorption of organic acids on (1010) ZnO surfaces. We have also employed this model to characterize native defects in ZnO nanowires. Finally we have demonstrated that the interaction of surface oxygen vacancies with organic acids may explain the suppression of photoluminescence anomalies observed for polymer coated ZnO nanowires.