Table 2.

Free energies at 298 kelvin in eV obtained at four levels of theory and referenced to the ADF fragment. Data that was used in the calculation of reaction free energies.

Exchange correlation potential
Species		PW91		OPBE		B3LYP		B3LYP*
G298 in eV referenced to ADF fragments
e− (pH 7)a		−4.36		−4.36		−4.36		−4.36
e− (pH 7, cyt. c2+)a		−4.56		−4.56		−4.56		−4.56
H+gas(corr)b		12.5672		12.5664		12.1597		12.2908
H+aq (pH 7)		0.5080		0.5074		0.1007		0.2318
H+aq (pH 3)		0.7440		0.7434		0.3367		0.4678
AZPVEb		0.288		0.284		0.288		0.285
H+aq (pH 7) −Δ ZPVE		0.2200		0.2234		−0.1873		−0.0532
H+aq (pH 3) −Δ ZPVE		0.456		0.4594		0.0487		0.1828
H2 at 1 atm gas		−6.8758		−6.8791		−7.6926		−7.4304
O2 at 1 atm gas		−10.1190		−10.4793		−11.8255		−10.9137
1 M O2 in water		−9.9450		−10.3065		−11.6535		−10.7417
H2O at 1 atm gas		−14.0886		−14.1346		−15.6997		−14.9567
Liquid H2Op		−14.7361		−14.7943		−16.3640		−15.6212
Liquid H2Os		−14.7361		−14.7943		−16.3640		−15.6212
H2O2 at 1 atm gas		−17.9326		−17.8934		−20.5087		−19.3356

^aExperimental

^bSee Appendix A

^pSignifies “passive” water, not formed from O₂. See Footnote ^s.

^sSignifies water formed from O₂, where G(H₂O^s) = G(H₂O^p).