Enthalpies of Formation of Some Gaseous Molecules, Atoms, and Free Radicals at 298 KaaUnless otherwise indicated, from D. R. Lide, CRC Handbook of Chemistry and Physics, 79th ed., CRC Press, Boca Raton, FL, 1998/1999, and Atkinson et al., J. Phys. Chem. Ref. Data, 26, 1329–1499 (1997).ccFor estimating heats of formation of other stable species, use group additivity methods described by S. W. Benson, Thermochemical Kinetics, Wiley, New York, 1976, see review of N. Cohen and S. W. Benson for organic compounds [“Estimation of Heats of Formation of Organic Compounds by Additivity Methods,” Chem. Rev., 93, 2419–2438 (1993)], and the paper by C.-J. Chen, D. Wong, and J. W. Bozzelli for chlorinated alkanes and alkenes [“Standard Chemical Thermodynamic Properties of Multichloro Alkanes and Alkenes: A Modified Group Additivity Scheme,” J. Phys. Chem. A, 102, 4551–4558 (1998)]. Application of group additivity to C2–C6 alkyl radicals is discussed by N. Cohen [“Thermochemistry of Alkyl for Radicals,” J. Phys. Chem., 96, 9052–9058 (1992)].