In comparing configurations with Cu 3 and Cu 4 atom clusters to Cu 1 and Cu 2 atom clusters, the competition between maximising metal-surface interaction energy and metal-metal interaction energy becomes more prominent. Similar to 1 and 2 atom adsorption, configurations with 3 and 4 Cu atoms which maximise the metal-metal interaction energy are the most stable adsorption structures. Therefore, it is unsurprising that Cu 3 and Cu 4 configurations which relax to two atom and single atom adsorption (such as Te-Wire-H, see figure ) are the least stable configurations, due to their smaller metal-metal interaction energies.