Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

Dihydrogen cation

Formula: [H2]+ (g)

CAS RN: 12184-90-6

ATcT ID: 12184-90-6*0

SMILES: [H][H+]

InChI: InChI=1S/H2/h1H/q+1

InChIKey: ZZIJOQHRUPVPQC-UHFFFAOYSA-N

Hills Formula: H2+

2D Image:

Aliases: [H2]+; Dihydrogen cation; Dihydrogen ion (1+); Hydrogen molecule cation; Hydrogen molecular ion (1+); Hydrogen cation; Hydrogen ion (1+); Molecular hydrogen cation; Molecular hydrogen ion (1+); Diatomic hydrogen cation; Diatomic hydrogen ion (1+)

Relative Molecular Mass: 2.01533 ± 0.00014

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
1488.364	1488.480	± 0.000	kJ/mol

3D Image of [H2]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [H2]+ (g)

The 9 contributors listed below account for 91.7% of the provenance of Δ_fH° of [H2]+ (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
48.9	66.13	H2 (g) → [H2]+ (g)	Δ_rH°(0 K) = 124417.49113 ± 0.00074 cm-1	Liu 2012, note unc
16.1	68.1	H2 (g, para) → H2 (g)	Δ_rH°(0 K) = 0.0 ± 0.0 cm-1	triv
6.1	80.1	H (g) → H+ (g)	Δ_rH°(0 K) = 109678.77174307 ± 0.00000020 cm-1	Mohr 2016, Sprecher 2010, note unc, Tiesinga 2021
6.1	80.2	H (g) → H+ (g)	Δ_rH°(0 K) = 109678.7717426 ± 0.0000020 cm-1	Liu 2009, note unc
5.2	70.1	H2 (g, ortho) → [H2]+ (g)	Δ_rH°(0 K) = 124299.00429 ± 0.00071 cm-1	Liu 2009, note unc, Hannemann 2006, Osterwalder 2004, Karr 2008, Korobov 2006, Korobov 2006a, Korobov 2008
2.9	74.1	[H2]+ (g, para) → [H2]+ (g)	Δ_rH°(0 K) = 0. ± 0. cm-1	Moss 1993b
2.5	84.2	[H2]+ (g) → H (g) + H+ (g)	Δ_rH°(0 K) = 21379.3501 ± 0.002 cm-1	Moss 1993b, Leach 1995, est unc
1.8	62.10	H2 (g) → 2 H (g)	Δ_rH°(0 K) = 36118.06962 ± 0.00074 cm-1	Liu 2012, note unc
1.8	62.16	H2 (g) → 2 H (g)	Δ_rH°(0 K) = 36118.069632 ± 0.000052 cm-1	Puchalski 2019, note unc

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [H2]+ (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
77.6	Hydron	H+ (g)	1528.084	1530.047	± 0.000	kJ/mol	1.007391 ± 0.000070	12408-02-5*0
59.2	Dihydrogen cation	[H2]+ (g, para)	1488.364	1488.480	± 0.000	kJ/mol	2.01533 ± 0.00014	12184-90-6*2
58.0	Dihydrogen	H2 (g, ortho)	1.417	0.019	± 0.000	kJ/mol	2.01588 ± 0.00014	1333-74-0*1
52.5	Dihydrogen cation	[H2]+ (g, ortho)	1489.060	1488.480	± 0.000	kJ/mol	2.01533 ± 0.00014	12184-90-6*1
52.3	Dihydrogen	H2 (g, para)	-0.000	-0.058	± 0.000	kJ/mol	2.01588 ± 0.00014	1333-74-0*2
22.6	Deuterium hydride cation	[HD]+ (g)	1490.498	1490.587	± 0.000	kJ/mol	3.021493 ± 0.000070	12181-16-7*0
22.2	Hydrogen atom	H (g)	216.034	217.998	± 0.000	kJ/mol	1.007940 ± 0.000070	12385-13-6*0
16.7	Deuterium hydride	HD (g)	0.328	0.319	± 0.000	kJ/mol	3.022042 ± 0.000070	13983-20-5*0
6.5	Hydride	H- (g)	143.264	145.228	± 0.000	kJ/mol	1.008489 ± 0.000070	12184-88-2*0
-1.7	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 [H2]+ (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
0.546	74.1	[H2]+ (g, para) → [H2]+ (g)	Δ_rH°(0 K) = 0. ± 0. cm-1	Moss 1993b
0.532	9082.1	[HeHH]+ (g) → He (g) + [H2]+ (g)	Δ_rH°(0 K) = 1775.42 ± 50 cm-1	De Fazio 2012, Papp 2017, Papp 2018, est unc
0.489	66.13	H2 (g) → [H2]+ (g)	Δ_rH°(0 K) = 124417.49113 ± 0.00074 cm-1	Liu 2012, note unc
0.486	70.1	H2 (g, ortho) → [H2]+ (g)	Δ_rH°(0 K) = 124299.00429 ± 0.00071 cm-1	Liu 2009, note unc, Hannemann 2006, Osterwalder 2004, Karr 2008, Korobov 2006, Korobov 2006a, Korobov 2008
0.266	85.10	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.1219937 ± 0.0000012 cm-1	Korobov 2017, note unc
0.266	85.9	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.121975 ± 0.000098 cm-1	Liu 2009, note unc, Korobov 2006, Korobov 2006a, Korobov 2008
0.133	9082.2	[HeHH]+ (g) → He (g) + [H2]+ (g)	Δ_rH°(0 K) = 1763.6 ± 100 cm-1	Sindelka 2003, est unc
0.133	9082.6	[HeHH]+ (g) → He (g) + [H2]+ (g)	Δ_rH°(0 K) = 1763.6 ± 100 cm-1	Kraemer 2002, Mrugala 2005, est unc
0.069	84.2	[H2]+ (g) → H (g) + H+ (g)	Δ_rH°(0 K) = 21379.3501 ± 0.002 cm-1	Moss 1993b, Leach 1995, est unc
0.066	85.6	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.1237 ± 0.002 cm-1	Taylor 1999a, Moss 1993b, Howells 1990, est unc
0.066	85.7	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.1237 ± 0.002 cm-1	Hijikata 2009, Moss 1993b, Howells 1990, est unc
0.066	85.4	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.1216 ± 0.002 cm-1	Frolov 1995, Moss 1993b, Howells 1990, est unc
0.066	85.5	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.1237 ± 0.002 cm-1	Gremaud 1998, Moss 1993b, Howells 1990, est unc
0.066	85.3	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.1237 ± 0.002 cm-1	Bishop 1985, Moss 1993b, Howells 1990, est unc
0.059	9082.4	[HeHH]+ (g) → He (g) + [H2]+ (g)	Δ_rH°(0 K) = 1793 ± 150 cm-1	McLaughlin 1979, Meuwly 1999, est unc
0.059	9082.3	[HeHH]+ (g) → He (g) + [H2]+ (g)	Δ_rH°(0 K) = 1754.3 ± 150 cm-1	Meuwly 1999, est unc
0.033	9082.5	[HeHH]+ (g) → He (g) + [H2]+ (g)	Δ_rH°(0 K) = 1710.5 ± 200 cm-1	Spirko 1995, Meuwly 1999, est unc
0.010	85.1	[H2]+ (g) → 2 H+ (g)	Δ_rH°(0 K) = 131058.121 ± 0.005 cm-1	Wolniewicz 1991
0.010	1853.8	HNNH (g, trans) → [H2]+ (g) + N2 (g)	Δ_rH°(0 K) = 13.304 ± 0.040 eV	Ruscic W1RO
0.004	66.12	H2 (g) → [H2]+ (g)	Δ_rH°(0 K) = 124417.488 ± 0.010 cm-1	Meisners 1994, Jungen 1990, de Lange 2002

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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
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]
7		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 [6] and Ruscic and Bross[7]).
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.