Geometrical and electronic structures of CunC±, CunC2± (n = 1-5) clusters: A first-principles study

The geometrical and electronic structures of CunC±, CunC2± (n = 1-5) clusters have been investigated using spin-polarized DFT calculations. There are much more differences in ground-state structures of CunC± (n = 2-5) and CunC2± (n = 1-4) clusters. The planar structure plays a dominated role in CunC2± (n = 1-5) clusters with two C atoms always bonding together, and leads to Cu clusters catalyzing carbon nanofibers effectively. The HOMO-LUMO energy gaps of CunC±, CunC2± (n = 1-5) clusters show obviously even-odd oscillation. According to the fragmentation energy of neutral and charged CunC, CunC2 (n = 1-5) clusters, we predict that the carbon nanofibers prepared in experiments are electropositive.