With density functional theory (DFT), the structures and stability of B_n clusters with n=2-8 have been studied. By using the all electron basis, all the geometries have been globally optimized without any symmetry constraint. It is found that all the small B_n (n=2-8) clusters prefer to form planar structures with sp² bonds, which are in good agreement with others' related studies. B_n and B_n^- are also compared. In contrast with the neutral Bn clusters, although B-B distances in Bn - have slight differences, but addition of one electron does not change their structures significantly. As for energies, all the anions are lying lower than their corresponding neutral clusters. In addition, calculations of energetic and electronic properties for all the neutral clusters have been presented. Both of these two properties show that in B_n (n=2-8), B₃ and B₅ are more stable than others. Vibrational spectra of B_n (n=3-8) clusters have also been discussed. In each spectrum, intensity peaks which are associated with the vibration of boron clusters related to B-B bond stretching can be observed and they are highest. However, among all the B_n clusters, such peaks of B₃ and B₅ show lower intensity than others. This results suggest that B₃ and B₅ are relatively more stable, which further demonstrates the conclusion above.

Date Published: 19 February 2009
PDF: 8 pages
Proc. SPIE 7279, Photonics and Optoelectronics Meetings (POEM) 2008: Optoelectronic Devices and Integration, 72790K (19 February 2009); doi: 10.1117/12.821155

Published in SPIE Proceedings Vol. 7279:
Photonics and Optoelectronics Meetings (POEM) 2008: Optoelectronic Devices and Integration
Liming Zhang; Michael J. O'Mahony, Editor(s)