A systematic survey of all possible c(10 x 6)-CN/ Cu(0 0 1) structures has been performed using density functional theory (DFT). A group of four preferred structures is presented with one of the structures identified as optimal. An analysis of the bonding within the optimal structure has shown that a significant localisation of the surface Cu 4s bonds occurs in the saturated system. (C) 2014 Elsevier B.V. All rights reserved.