Solution energies for a series of divalent cations (Mg, Co, Ca, Cd, Sr, Ba) in four perovskite oxides were predicted using atomic scale computer simulation. The host compounds considered were LaScO3, LaInO3, GdScO3 and GdInO3, in which both the A and the B cations adopt formal 3(+) valence states. In each case, it is predicted that divalent cations are charge compensated by oxygen vacancies. However, for each dopant ion, the preferred solution site within the perovskites depends not only upon the solution cation radius, but also the crystallography of the host lattice. (C) 2004 Elsevier B.V. All rights reserved.