Structure and stability of small ZnCn clusters

A theoretical study of the small ZnCn (n = 1-8) clusters has been carried out at the B3LYP/6-311+G(d) level. Different molecular properties for open-chain and cyclic species have been calculated. The computed properties include electronic energies, vibrational frequencies, dipole moments, and rotational constants for individual species. In addition, the relative stability of the different clusters is also discussed in terms of the incremental binding energy. In the case of open-chain clusters, the lowest-lying states correspond to triplet states with the exception of ZnC2, whereas the electronic ground state is found to be a singlet state for cyclic clusters. The incremental binding energy graph shows a smooth even-odd parity effect in the incremental binding energy, n-even species being, in general, more stable than the adjacent odd-numbered ones. It was also found that the first members in the series, excepting ZnC2, prefer open-chain structures, whereas when n >= 6 cyclic ground states are favored.