First-principles study of the electronic structures of icosahedral Ti _N(N = 13,19,43,55) clusters

A real-space first-principles density functional for molecules (DMoI) based on density functional theory with the GGA was employed for studying the electronic structures of the icosahedral, hexagonal close-packed, and fcc close-packed Ti_N clusters. The icosahedral structures were found to be favorable in energy except for Ti₄₃. The atomic cells showed complex expanding or shrinking behaviors with increase of cluster size. The bonding between the different atomic shells was found to be more important for the binding property of icosahedral structure.