Local properties, such as partial charges or local spins, are an important concept in chemistry. In this work, two alternative local decomposition schemes for molecular total spin expectation values <(S) over cap (2)> are compared for Kohn-Sham density functional theory calculations on polynuclear transition-metal clusters. It is confirmed that the scheme proposed by Mayer resolves the problem of the non-zero local spins <(S) over cap (2)(A)> which arise in the first approach of this kind suggested by Clark and Davidson. Furthermore, it is demonstrated that Mayer's <(S) over cap (2)(A)> expectation values can be interpreted as S-A(S-A + 1). The cross-terms, <(S) over cap (A) . (S) over cap (B)>(A not equal B), are very similar in both schemes when calculated for two metal atoms in polynuclear clusters, whereas they differ for small open-shell molecules such as NO. Overall, Mayer's approach is more consistent for the local decomposition of <(S) over cap (2)>. (C) 2007 Elsevier B.V. All rights reserved.