Carbon Substitution on N₂₄ Cages: Crossover between Triangular and Hexagonal Structures

Table 4

Heat of formation for N₂₀C₄, N₁₈C₆, and N₁₆C₈. Energies are calculated using CCSD(T)//HF energies. Energies are in kcal/mol and kcal/g.

Molecule	Isomer	Δ𝐻𝑓; (kcal/mol)	Δ𝐻𝑓; (kcal/g)
N20C4; (M = 328 g/mol)	T1	+1003.8	+3.06
	T2	+1010.5	+3.08
	S1	+1030.3	+3.14
	S2	+1020.3	+3.11
	H1	+1059.0	+3.23
	H2	+1047.8	+3.19
	H3	+1046.4	+3.19
	H4	+1044.7	+3.19
N18C6; (M = 324 g/mol)	T	+988.0	+3.05
	S	+948.5	+2.93
	H1	+962.0	+2.97
	H2	+963.3	+2.97
N16C8; (M = 320 g/mol)	S	+880.1	+2.75
	H1	+875.5	+2.74
	H2	+879.3	+2.75