Density functional study of W2 and W3 clusters

Equilibrium geometries, electron affinities and dissociation energies of W2, W2−, W3 and W3− clusters and harmonic vibrational frequencies of W2 and W2− clusters were studied by density functional methods B3LYP, B3PW91, BLYP, BHLYP, B3P86 and MPW1PW91. The results indicate that singlet state is the ground state for W2 cluster, and doublet for W2− cluster. For W3 and W3− clusters, triplet with D3h symmetry and doublet with C2v symmetry are the ground state, respectively. Comparing among different methods, the results indicate that the calculated quantities, such as electron affinity and dissociation energy, are sensitive to the methods used and cluster size.