Determination of the TiO2 (110) (2x3) surface structure via a parametric approach to STM image simulation

Scanning tunneling microscopy (STM) image simulations for transition-metal oxide surfaces have been compared to STM images to determine the atomic str ucture of the TiO2 (110) (2X3) reconstruction. The calculation of simulated image contrast is based on fitting Slater-type orbital functions to first- principles empty state contours for an umreconstructed TiO2 (110). The calc ulations are extended to arbitrary surface structures using a parametric ap proach. For the case of TiO2 (110), simulations of empty conduction-band ed ge state densities are compared with STM images to distinguish between two possible atomic terminations of the 2 x 3 surface. The method is proposed a s a general approach that allows a first-order interpretation of features i n STM images of complex oxide surfaces. The structures of these surfaces ar e often quite complex and exhibit a mixture of ionic and covalent bonding, often making image interpretation difficult.