First-principles calculations of the structural, electronic and magnetic properties of BnN20−n (n = 6−18) clustersJ.R. Li, Y.W. Mu, J.G. Wan, F.Q. Song, M. Han and G.H. WangEur. Phys. J. D, 63 2 (2011) 201-207DOI: https://doi.org/10.1140/epjd/e2011-10559-8