%0 conference lecture %@ %A Michl, A., Ferstl, P., Hammer, L., Schneider, M.A., Mueller, S. %D 2014 %J Kondensierte Materie, DPG Fruehjahrstagung 2014 %T Ground-state structures for oxygen adsorption on Ir(100)-(1x1) investigated via the cluster-expansion method %U %X