Assessing the validity of theoretical results

We present recent theoretical results for the V-3 and Au-4 clusters. Calcul ations of the V-3 doublet system indicate that the 6-311+G(d) basis set is sufficiently flexible to provide reliable minimum energy structures and vib rational frequencies, that these structures and frequencies are insensitive to spin contamination of the wave function when the BPW91 functional is us ed, and that changing to the B3LYP functional may result in very different structures and frequencies. A computationally less expensive scalar relativ istic treatment of An(4) Clusters gives structural properties that are in g ood agreement with those obtained using a four-component method.