Using surface x-ray diffraction (SXRD), quantitative low-energy electron diffraction (LEED), and
density-functional theory (DFT) calculations, we have determined the structure of the (4 × 1)
reconstruction formed by sputtering and annealing of the SnO2ð110Þ surface. We find that the
reconstruction consists of an ordered arrangement of Sn3O3 clusters bound atop the bulk-terminated
SnO2ð110Þ surface. The model was found by application of a DFT-based evolutionary algorithm with
surface compositions based on SXRD, and shows excellent agreement with LEED and with previously
published scanning tunneling microscopy measurements. The model proposed previously consisting of inplane
oxygen vacancies is thus shown to be incorrect, and our result suggests instead that Sn(II) species in
interstitial positions are the more relevant features of reduced SnO2ð110Þ surfaces
