1. Kos, A.J.; Jemmis, E.D.; Schleyer, P.v.R.; Gleiter, R.; Fischbach, U.; Pople, J.A.: 1981, J. Am. Chem. Soc. 103, p.4996; Apeloig, Y.; Clark, T.; Kos, A.J.; Jemmis, E.D.; Schleyer, P.v.R.: 1980, Israel J. Chem. 20, p. 43. This paper lists earlier references.
2. Lewis, G.N.: 1916, J. Am. Chem. Soc. 38, p. 762; Kossel, W.: 1916, Ann. Phys. 49, p. 229.
3. Gaussian 76: Binkley, J.S.; Whiteside, R.; Hariharan, P.C.; Seeger, R.; Pople, J.A.; Hehre, W.J.; Newton, M.D.: 1979, QCPE 11, 368; Gaussian 80: Binkley, J.S.; Whiteside, R.; Krishnan, R.; Seeger, R.; DeFrees, D.J.; Schlegel, H.B.; Topiol, S.; Kahn, L.R.; Pople, J.A.: 1981, QCPE 10, 416.
4. Pople, J.A.; Binkley, J.S.; Seeger, R.: 1976, Int. J. Quant. Chem. Symp. 10, p. 1. For the 3-21G basis set, see Binkley, J.S.; Pople, J.A.; Hehre, W.J.: 1980, J. Am. Chem. Soc. 102, p. 939. For absolute energies and fuller descriptions of most of the species in the present paper, see the “Carnegie-Mellon Quantum Chemistry Archive”, Whiteside, R.A.; Frisch, M.J.; Binkley, J.S.; DeFrees, D.J.; Schlegel, H.B.; Raghavachari, K.; Pople, J.A.: 1981, 2nd Ed., Carnegie-Mellon University.
5. Pauling, L.A.: 1937, J. Am. Chem. Soc. 53, p. 1367.