Charged titanium-doped carbon clusters: Structures and energetics

The structures and stabilities of TiCn+/− (n = 1–8) clusters have been studied by density functional theory (DFT) using the hybrid B3LYP functional. Molecular properties for three different isomers, linear, cyclic and fan species have been computed. The fan isomers, where the titanium atom interacts with the whole carbon chain, are predicted generally, to be more stable than both linear and cyclic structures. For linear and fan TiCn+/− isomers an even-odd alternation in stability is found, isomers with n-even being in general more stable than the adjacent n-odd numbered. The ionization potentials and electron affinities of linear and fan TiCn clusters also show an even–odd parity effect. Generally n-odd clusters have higher ionization potentials than the n-even ones whereas the electron affinities show an opposite alternation trend, n-even systems having higher values than the adjacent n-odd ones.