We have investigated detailed electronic states of acetonitrile (MeCN) molecule adsorption on the anatase (101) TiO2 surface by using the density functional theory with a hybrid exchange correlation functional for deeper understanding of dye-sensitized solar cells interfaces. Our analysis indicates that the 7a(1) orbital of MeCN hybridizes with the non-bonding orbitals of threefold coordinated oxygen (O-3C) on the surface, not directly to the fivefold coordinated Ti (Ti-5C). This mechanism accounts for the stable adsorption geometry of MeCN and the coverage of MeCN molecules on the surface. (C) 2012 Elsevier B. V. All rights reserved.