(i) the removal of 2 one-fold carbons, namely, C1 and C2 thus creating two C vacancies in C 16 , and (ii) the replacement of C5-C6 by N. The results of the geometry optimization onto the ground state are shown in Table . There are changes in the 4j and 4k nitrogen positions which slightly depart from the ¼ value in B 8 N 8 (and C 16 ). Nevertheless, the symmetry is preserved (P-4m2), and there is a unique C-N distance of d(C-N) = 1.480 Å.