21. Decreasing the number of the B 6 octahedra diminishes the role of nitrogen because the C-B-C chains start bridging the icosahedra . 22. There are two inequivalent B 12 icosahedra , I1 and I2, which are constructed by the B1 B5 and B8 B12 sites, respectively. 23. The ?-phase can be described as a NaCl-type arrangement of two types of clusters, B 12 icosahedra and B 2 pairs. 24. These icosahedra arrange in a thirteen-icosahedron unit ( B 12 ) 12 B 12 which is shown in figure 4a and is called supericosahedron. 25. L1 consists of the icosahedra I3, I4 and I5 and the C65 " dimer ", and L2 consists of the icosahedra I2 and I6. 26. L1 consists of the icosahedra I3, I4 and I5 and the C65 " dimer ", and L2 consists of the icosahedra I2 and I6. 27. The boron cubic sub lattice contains super icosahedra made up of a central B 12 icosahedra surrounded by 12 others, B 12 ( B 12 ) 12. 28. The boron cubic sub lattice contains super icosahedra made up of a central B 12 icosahedra surrounded by 12 others, B 12 ( B 12 ) 12. 29. Instead, they bond to the B 12 icosahedra in the neighboring layer, and this decreases bonding strength in the " c "-plane. 30. An unusual linkage is depicted in figure 8b, where two B 12-I5 icosahedra connect via two B atoms of each icosahedron forming an imperfect square.
