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:The boron atoms lie on each vertex of the octahedron and are sp hybridized. One sp-hybrid radiates away from the structure forming the bond with the hydrogen atom. The other sp-hybrid radiates into the center of the structure forming a large bonding molecular orbital at the center of the cluster. The remaining two unhybridized orbitals lie along the tangent of the sphere like structure creating more bonding and antibonding orbitals between the boron vertices. The orbital diagram breaks down as follows:
::The 18 framework molecular orbitals, (MOs), derived from the 18 boron atomic orbitals are:
::*1 bonding MO at the center of the cluster and 5 antibonding MOs from the 6 sp-radial hybrid orbitals
::*6 bonding MOs and 6 antibonding MOs from the 12 tangential p-orbitals.
:The total skeletal bonding orbitals is therefore 7, i.e. .