Structure of a low-lying isomer of BOSi$_2$, as a free-space planar   cluster, using the Hartree-Fock method plus second order perturbations
  The Hartree-Fock (HF) method, supplemented by low-order Moller-Plesset (MP2) perturbation theory, has been utilized to predict the nuclear geometry, assuming planarity, of a low-lying isomer of the free space cluster BOSi$_2$. The planar structure found at equilibrium geometry is shown to be stable against small amplitude molecular vibrations. Finally, some brief comments are made on the possible relevance of the above free-space cluster geometry to the known B-O defects which limit the improvement of minority carrier lifetime in a form of p-type silicon. 
G. Forte, G. G. N. Angilella, N. H. March, R. Pucci
physics.atm-clus