Structures and Properties of CoB19+/0/– Clusters

A global search for the lowest energy structure of Co atom-doped boron clusters (CoB 19 + , CoB 19 , and CoB 19 - clusters) was conducted. The lowest energy structures of them are remarkably different from those of B 20 and CoB 18 - clusters. CoB 19 + clusters have a bowl-shaped geometry, where the Co atom is at the bottom of the bowl and is coordinated with eight B atoms. The CoB 19 cluster presents seven- and eight-membered B rings. The CoB 19 - cluster can be viewed as a structure that evolves from a Co-doped boron plane. The coordination number of CoB 19 and CoB 19 - clusters are 16 and 14, respectively. Several low-lying isomers have quasi-planar structures for the CoB 19 - cluster. Some properties including charge transformation and distribution, HOMO-LUMO gaps, molecular orbital distribution, and stability of neutral CoB 19 are discussed. CoB 19 + and CoB 19 - exhibit magnetism with a net moment of 1.0 and 0.94 μ B because of odd number of electrons.