Structures and stabilities of GaCn (n = 1–10) clusters

A theoretical study of the small Gallium-doped carbon clusters GaCn (n = 1–10) has been studied with density functional theory (DFT) method at the B3LYP/6-311+G* level. The computed properties include equilibrium geometries, electronic energies, vibrational frequencies, dipole moments, and rotational constants for individual species. According to these calculations, except for smaller GaC2, the open-chain linear or quasi-linear isomers with the Gallium atom bound to the end of the carbon chain are the most stable geometry in all cases. The electronic ground state is found to be a doublet state for the GaCn clusters, with the only exception of the smallest GaC. The incremental binding energy diagram shows a strong even–odd alternation in the cluster stability for these linear GaCn, with their n-even members being much more stable than the adjacent odd-numbered ones. These parity effects also appear in the second difference in energy curves. In addition, by comparing with the fragmentation energies accompanying various channels, the most favorable dissociation channels are acquired.