Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Dihydrogen

Formula: H2 (g, para)
CAS RN: 1333-74-0
ATcT ID: 1333-74-0*2
SMILES: [H][H]
InChI: InChI=1S/H2/h1H
InChIKey: UFHFLCQGNIYNRP-UHFFFAOYSA-N
Hills Formula: H2

2D Image:

[H][H]
Aliases: H2; Dihydrogen; Hydrogen molecule; Hydrogen; Molecular hydrogen; Diatomic hydrogen; o-Hydrogen; p-Hydrogen
Relative Molecular Mass: 2.01588 ± 0.00014

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
-0.000-0.058± 0.000kJ/mol

3D Image of H2 (g, para)

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Top contributors to the provenance of ΔfH° of H2 (g, para)

The 6 contributors listed below account for 91.5% of the provenance of ΔfH° of H2 (g, para).

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
58.768.1 H2 (g, para) → H2 (g) ΔrH°(0 K) = 0.0 ± 0.0 cm-1triv
13.466.13 H2 (g) → [H2]+ (g) ΔrH°(0 K) = 124417.49113 ± 0.00074 cm-1Liu 2012, note unc
9.570.1 H2 (g, ortho) → [H2]+ (g) ΔrH°(0 K) = 124299.00429 ± 0.00071 cm-1Liu 2009, note unc, Hannemann 2006, Osterwalder 2004, Karr 2008, Korobov 2006, Korobov 2006a, Korobov 2008
5.274.1 [H2]+ (g, para) → [H2]+ (g) ΔrH°(0 K) = 0. ± 0. cm-1Moss 1993b
2.972.1 H2 (g, para) → [H2]+ (g, para) ΔrH°(0 K) = 124417.491098 ± 0.000062 cm-1Beyer 2019, note unc
1.680.1 H (g) → H+ (g) ΔrH°(0 K) = 109678.77174307 ± 0.00000020 cm-1Mohr 2016, Sprecher 2010, note unc, Tiesinga 2021

Top 10 species with enthalpies of formation correlated to the ΔfH° of H2 (g, para)

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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
83.4 DihydrogenH2 (g, ortho)[H][H]1.4170.019± 0.000kJ/mol2.01588 ±
0.00014
1333-74-0*1
71.0 Dihydrogen cation[H2]+ (g, ortho)[H][H+]1489.0601488.480± 0.000kJ/mol2.01533 ±
0.00014
12184-90-6*1
66.7 Dihydrogen cation[H2]+ (g, para)[H][H+]1488.3641488.480± 0.000kJ/mol2.01533 ±
0.00014
12184-90-6*2
52.3 Dihydrogen cation[H2]+ (g)[H][H+]1488.3641488.480± 0.000kJ/mol2.01533 ±
0.00014
12184-90-6*0
40.6 HydronH+ (g)[H+]1528.0841530.047± 0.000kJ/mol1.007391 ±
0.000070
12408-02-5*0
11.8 Deuterium hydride cation[HD]+ (g)[H][2H+]1490.4981490.587± 0.000kJ/mol3.021493 ±
0.000070
12181-16-7*0
11.6 Hydrogen atomH (g)[H]216.034217.998± 0.000kJ/mol1.007940 ±
0.000070
12385-13-6*0
8.7 Deuterium hydrideHD (g)[H][2H]0.3280.319± 0.000kJ/mol3.022042 ±
0.000070
13983-20-5*0
3.4 HydrideH- (g)[H-]143.264145.228± 0.000kJ/mol1.008489 ±
0.000070
12184-88-2*0

Most Influential reactions involving H2 (g, para)

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
0.58768.1 H2 (g, para) → H2 (g) ΔrH°(0 K) = 0.0 ± 0.0 cm-1triv
0.47072.1 H2 (g, para) → [H2]+ (g, para) ΔrH°(0 K) = 124417.491098 ± 0.000062 cm-1Beyer 2019, note unc
0.20669.7 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.486837 ± 0.000222 cm-1Jennings 1987, note unc
0.20669.10 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.4868127 ± 0.0000022 cm-1Puchalski 2019, note unc
0.20669.8 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.48680 ± 0.00022 cm-1Piszczatowski 2009, note unc
0.20669.5 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.487 ± 0.001 cm-1Schwartz 1987
0.00269.3 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.48 ± 0.01 cm-1Huber 1979, est unc
0.00069.4 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.50 ± 0.02 cm-1Dabrowski 1984, est unc
0.00069.2 H2 (g, para) → H2 (g, ortho) ΔrH°(0 K) = 118.495 ± 0.02 cm-1Herzberg 1960, est unc
0.00073.1 H2 (g, para) → [H2]+ (g, ortho) ΔrH°(0 K) = 124476.0 ± 0.5 cm-1Herzberg 1972, est unc


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 and D. H. Bross,
Active Thermochemical Tables (ATcT) values based on ver. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument,
Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide
J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
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.