Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Hydrogen atom

Formula: H (g)

CAS RN: 12385-13-6

ATcT ID: 12385-13-6*0

SMILES: [H]

InChI: InChI=1S/H

InChIKey: YZCKVEUIGOORGS-UHFFFAOYSA-N

Hills Formula: H1

2D Image:

Aliases: H; Hydrogen atom; Protium; Hydrogen; Atomic hydrogen; Hydrogen radical; Monohydrogen; H-atom

Relative Molecular Mass: 1.007940 ± 0.000070

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
216.034	217.998	± 0.000	kJ/mol

3D Image of H (g)

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

The 5 contributors listed below account for 91.9% of the provenance of Δ_fH° 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 Reference acts as a further link to the relevant references and notes 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 (%)	TN ID	Reaction	Measured Quantity	Reference
37.3	62.10	H2 (g) → 2 H (g)	Δ_rH°(0 K) = 36118.06962 ± 0.00074 cm-1	Liu 2012, note unc
37.3	62.16	H2 (g) → 2 H (g)	Δ_rH°(0 K) = 36118.069632 ± 0.000052 cm-1	Puchalski 2019, note unc
9.3	62.15	H2 (g) → 2 H (g)	Δ_rH°(0 K) = 36118.0695 ± 0.0020 cm-1	Piszczatowski 2009, note unc
3.9	80.2	H (g) → H+ (g)	Δ_rH°(0 K) = 109678.7717426 ± 0.0000020 cm-1	Liu 2009, note unc
3.9	80.1	H (g) → H+ (g)	Δ_rH°(0 K) = 109678.77174307 ± 0.00000020 cm-1	Mohr 2016, Sprecher 2010, note unc, Tiesinga 2021

Top 10 species with enthalpies of formation correlated to the Δ_fH° of H (g)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Correlation Coefficent (%)	Species Name	Formula	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
29.2	Hydride	H- (g)	143.264	145.228	± 0.000	kJ/mol	1.008489 ± 0.000070	12184-88-2*0
26.0	Hydron	H+ (g)	1528.084	1530.047	± 0.000	kJ/mol	1.007391 ± 0.000070	12408-02-5*0
22.2	Dihydrogen cation	[H2]+ (g)	1488.364	1488.480	± 0.000	kJ/mol	2.01533 ± 0.00014	12184-90-6*0
13.1	Dihydrogen cation	[H2]+ (g, para)	1488.364	1488.480	± 0.000	kJ/mol	2.01533 ± 0.00014	12184-90-6*2
13.0	Deuterium hydride	HD (g)	0.328	0.319	± 0.000	kJ/mol	3.022042 ± 0.000070	13983-20-5*0
12.9	Dihydrogen	H2 (g, ortho)	1.417	0.019	± 0.000	kJ/mol	2.01588 ± 0.00014	1333-74-0*1
12.0	Deuterium hydride cation	[HD]+ (g)	1490.498	1490.587	± 0.000	kJ/mol	3.021493 ± 0.000070	12181-16-7*0
11.6	Dihydrogen cation	[H2]+ (g, ortho)	1489.060	1488.480	± 0.000	kJ/mol	2.01533 ± 0.00014	12184-90-6*1
11.6	Dihydrogen	H2 (g, para)	-0.000	-0.058	± 0.000	kJ/mol	2.01588 ± 0.00014	1333-74-0*2
1.3	Deuterium atom cation	D+ (g)	1532.210	1534.123	± 0.000	kJ/mol	2.01355319809 ± 0.00000000040	14464-47-2*0

Most Influential reactions involving H (g)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence Coefficient	TN ID	Reaction	Measured Quantity	Reference
1.000	9398.1	H (g) → H (ad, Pt(111) atop)	Δ_rH°(0 K) = -2.57 ± 0.20 eV	Kandoi 2006, Greeley 2002, Greeley 2004, est unc
1.000	8952.6	NeH (g) → Ne (g) + H (g)	Δ_rH°(0 K) = 3.77 ± 2 cm-1	Harris 2014, est unc
0.996	81.6	H- (g) → H (g)	Δ_rH°(0 K) = 6083.064145 ± 0.000030 cm-1	Drake 1999, Andersen 1999, Feller 2016
0.957	2312.1	CH4 (g) → [CH3]+ (g) + H (g)	Δ_rH°(0 K) = 14.32271 ± 0.00013 eV	Chang 2017
0.942	78.1	[H2]- (g) → H (g) + H- (g)	Δ_rH°(0 K) = 8819.364 ± 100 cm-1	Srivastava 2012, est unc
0.931	4472.1	CH3OOH (g) → [CH2OOH]+ (g) + H (g)	Δ_rH°(0 K) = 11.647 ± 0.005 eV	Covert 2018
0.927	2365.1	[CH]+ (g) → C+ (g) + H (g)	Δ_rH°(0 K) = 32946.7 ± 0.6 cm-1	Cho 2016, note unc
0.897	175.1	[OH]+ (g) → O+ (g) + H (g)	Δ_rH°(0 K) = 40412.0 ± 2.2 cm-1	Moselhy 1975, note unc
0.889	6533.1	CHFO (g) → FCO (g) + H (g)	Δ_rH°(0 K) = 34950 ± 20 cm-1	Maul 1999
0.872	2567.5	HCCH (g) → [CCH]+ (g) + H (g)	Δ_rH°(0 K) = 17.3576 ± 0.0010 eV	Jarvis 1999, Weitzel 2001
0.807	789.1	[HCl]+ (g) → H (g) + Cl+ (g)	Δ_rH°(0 K) = 37537.0 ± 0.5 cm-1	Michel 2002, note HCl
0.793	3179.1	CH3CH2CH3 (g) → [CH3CHCH3]+ (g) + H (g)	Δ_rH°(0 K) = 11.624 ± 0.002 eV	Stevens 2010
0.775	1656.1	NH4 (g) → NH3 (g) + H (g)	Δ_rH°(0 K) = -0.130 ± 0.005 eV	Aue 1972
0.720	9380.2	PtH (g) → Pt (g) + H (g)	Δ_rH°(0 K) = 329.6 ± 3.9 kJ/mol	Irikura 2023
0.675	2366.1	[CH]- (g) → C- (g) + H (g)	Δ_rH°(0 K) = 78.83 ± 0.06 kcal/mol	Feller 2016, note unc2
0.635	9382.1	[PtH]+ (g) → Pt+ (g) + H (g)	Δ_rH°(0 K) = 279.3 ± 5.7 kJ/mol	Irikura 2023
0.611	2918.1	CH3OH (g) → [CH2OH]+ (g) + H (g)	Δ_rH°(0 K) = 11.6454 ± 0.0017 eV	Borkar 2011
0.609	164.3	H2O (g) → OH (g) + H (g)	Δ_rH°(0 K) = 41145.92 ± 0.12 cm-1	Boyarkin 2013
0.605	2101.1	HNNN (g) → H (g) + NNN (g)	Δ_rH°(0 K) = 30970 ± 50 cm-1	Cook 1999
0.598	1940.4	HNO (g) → H (g) + NO (g)	Δ_rH°(0 K) = 16450 ± 10 cm-1	Dixon 1981, Dixon 1984, Dixon 1996

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 21^st Century. J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3		B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
5		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]
6		B. Ruscic and D. H. Bross, Thermochemistry Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula

The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

Uncertainties

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [5] and Ruscic and Bross[6]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.000₅ kJ/mol.

Website Functionality Credits

The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/.

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.