  Surfaces of rutile-like RuO2, especially the most stable (110) surface, are
important for catalysis, sensing and charge storage applications. Structure,
chemical composition, and properties of the surface depend on external
conditions. Using the evolutionary prediction method USPEX, we found stable
reconstructions of the (11) surface. Two stable reconstructions, RuO4-(2x1) and
RuO2-(1x1), were found, and the surface phase diagram was determined. The new
RuO4-(2x1) reconstruction is stable in a wide range of environmental
conditions, its simulated STM image perfectly matches experimental data, it is
more thermodynamically stable than previously proposed reconstructions, and
explains well pseudocapacitance of RuO2 cathodes.
