It was shown that the removal of 0.2 monolayers of a clean well-ordered Au(110) surface at room temperature led to the formation of vacancy islands with 2 different types of step along one direction: a so-called (111)-step on one side and a (331)-step on the other side; both along the [1¯10]-direction. The consequences of this broken mirror symmetry were considered, and it was found that these vacancy islands had a two-fold symmetrical equilibrium shape; in spite of their structure having only one-fold symmetry.

Shape and Evolution of Vacancy Islands on a Missing Row Reconstructed Surface - Au(110). M.J.Rost, S.B.Van Albada, J.W.M.Frenken: Surface Science, 2002, 518[1-2], 21-38