A method for the automatized localization of proton sites in a crystal structure and of probable proton transport pathways is developed from a slightly modified bond valence (BV) concept that in contrast to conventional parameter sets accounts for the polarizabilities of the interacting particles. The method is tested for several recent structure determinations of inorganic solids with mobile protons. Peculiarities of the application to mixed conductors are discussed for the hydrogen molybdenum bronze phase H0.95MoO3. (C) 2003 Elsevier B.V. All rights reserved.