Static and dynamic polarizabilities of (CdSe)n (n = 1–16) clusters

Density functional theoretical calculations have been performed on small and medium-sized (CdSe)n (n = 1–16) clusters in order to evaluate the variation in electric polarizability and anisotropy in polarizability with increase in the cluster size at both static and Nd:YAG laser frequencies. The electric polarizability values at static frequency show a rapid decrease up to heptamer only with the exception observed for (CdSe)5 clusters where a sudden increase in the polarizability value is observed. An even–odd oscillating behavior is observed in the anisotropy values between the dimer and heptamer CdSe clusters. Apart from polarizability and anisotropy calculations, the variation in the energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital and second difference of energies with the cluster size have also been calculated. Just like the anisotropy values, an even–odd oscillating behavior is also observed in the second difference value for the smaller CdSe clusters.