Selected ATcT [1, 2] enthalpy of formation based on version 1.118 of the Thermochemical Network [3]

This version of ATcT results was partially described in Ruscic et al. [4], and was also used for the initial development of high-accuracy ANLn composite electronic structure methods [5].

Species Name Formula    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
Hydrogen atomH (g)216.034217.998± 0.000kJ/mol1.007940 ±
0.000070		12385-13-6*0

Top contributors to the provenance of ΔfH° of H (g)

The 9 contributors listed below account for 90.2% of the provenance of ΔfH° of H (g).

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The listed Reaction acts as a link to the relevant references for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution
(%)		 Reaction Measured Quantity
46.2 H2 (g) → 2 H (g) ΔrH°(0 K) = 36118.0695 ± 0.0020 cm-1
11.9 H2 (g, para) → H2 (g) ΔrH°(0 K) = 0.0 ± 0.0 cm-1
11.9 H2 (g, ortho) → [H2]+ (g) ΔrH°(0 K) = 124299.00429 ± 0.00071 cm-1
4.6 H (g) → H+ (g) ΔrH°(0 K) = 109678.771671 ± 0.000010 cm-1
4.6 H (g) → H+ (g) ΔrH°(0 K) = 109678.7717426 ± 0.0000020 cm-1
4.6 H (g) → H+ (g) ΔrH°(0 K) = 109678.771690 ± 0.000006 cm-1
2.8 [H2]+ (g) → H (g) + H+ (g) ΔrH°(0 K) = 21379.3501 ± 0.002 cm-1
1.8 H2 (g) → 2 H (g) ΔrH°(0 K) = 36118.062 ± 0.010 cm-1
1.5 [H2]+ (g) → 2 H+ (g) ΔrH°(0 K) = 131058.121975 ± 0.000098 cm-1
References
1   B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner,
Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited.
J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2   B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner,
Active Thermochemical Tables: Thermochemistry for the 21st Century.
J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3   B. Ruscic, Active Thermochemical Tables (ATcT) values based on ver. 1.118 of the Thermochemical Network (2015); available at ATcT.anl.gov
4   B. Ruscic,
Active Thermochemical Tables: Dissociation Energies of Several Homonuclear First-Row Diatomics and Related Thermochemical Values.
Theor. Chem. Acc. 133, 1415/1-12 (2005) [DOI: 10.1007/s00214-013-1415-z]
5   S. J. Klippenstein, L. B. Harding, and B. Ruscic,
Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.
J. Phys. Chem. A in preparation (2016)
6   B. Ruscic,
Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables.
Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
Acknowledgement
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.