B12Hn and B12Fn: Planar vs Icosahedral Structures
  Using density functional theory (DFT) and quantum Monte Carlo (QMC) calculations we show that the B12Hn and B12Fn (n = 0-4) quasi-planar structures are energetically more favorable than the corresponding icosahedral clusters. Moreover, we show that the fully planar B12F6 cluster is more stable than the 3D counterpart. These results open up the possibility of designing larger boron based nanostructures starting from quasi-planar or fully planar building blocks. 
N. Gonzalez Szwacki and C. J. Tymczak
cond-mat.mes-hall cond-mat.mtrl-sci physics.atm-clus