Fig. 1. Side (left) and top (right) view of the free standing ZnO(1011̄0) surface after relaxation. The arrows denote the direction of the surfaces. The numbers correspond to the different adsorption sites investigated. The Zn and O atoms are given in dark gray, and red, respectively. The same color coding will be used throughout. On the right panel, the surface atoms are given in darker colors compared to the rest.