For the study of small Cu n clusters, we have selected five typical Cu 2 and Cu 4 geometries. All geometries are initially adsorbed at the most favourable single atom adsorption site for each surface. There are two Cu 2 models, "close" and "apart" where two Cu atoms are adsorbed either at neighbouring sites or separated by two unoccupied sites. This is a very basic model to determine an initial preference towards association or separation. For Cu 4 , we chose three different models. These are (i) a line along equivalent adsorption sites, (ii) a flat rhombus configuration or (iii) a 3D tetrahedron. This lets us determine any initial preference towards 2D or 3D structures and shows how Cu-Cu interactions compare to Cu-surface interactions (see Equations 3 and 4). Analysis of the competition between these two interactions allows us to select the surfaces most likely to promote wetting of Cu for further study.