As a follow-up to previous work on boron–nitrogen rings, four ab initio calculational methods were used to determine geometric, thermodynamic, and spectroscopic properties of azatriboretidine and triazaboretidine. Of the four possible conformations, the two presented in this paper are the only ones whose complete characterization was possible. The enthalpy of combustion results indicate that azatriboretidine gives off about 54 kJ/g, making it a better high energy material than the other compounds studied in the previous two studies. Triazaboretidine only gave off 33.6 kJ/g of energy.