Selected ATcT [1, 2] enthalpy of formation based on version 1.122g of the Thermochemical Network [3]

This version of ATcT results was generated from an expansion of version 1.122e [4] to include results centered on the determination of the appearance energy of CH3+ from CH4. [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
Trihydrogen(H)(HH) (g, vdW)[H]1[H][H]1215.9218.3± 1.1kJ/mol3.02382 ±
0.00021		12184-91-7*100

Representative Geometry of (H)(HH) (g, vdW)

spin ON           spin OFF
          

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

The 14 contributors listed below account for 90.0% of the provenance of ΔfH° of (H)(HH) (g, vdW).

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
20.280.7 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -55 ± 200 cm-1Pavanello 2009b, Cafiero 2001, Ruscic anh, est unc
20.281.1 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 74759 ± 200 cm-1Pavanello 2009b, Matyus 2007, est unc
8.980.9 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -52 ± 300 cm-1Mielke 2002, est unc
8.980.8 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -55 ± 300 cm-1Partridge 1993, est unc
7.781.6 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.261 ± 0.040 eVRuscic W1RO
2.980.6 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.15 ± 1.5 kcal/molTruhlar 1978, Siegbahn 1978, Liu 1973, est unc
2.980.5 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.24 ± 1.50 kcal/molRuscic W1RO
2.979.5 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 103.10 ± 1.50 kcal/molRuscic W1RO
2.580.4 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.03 ± 1.60 kcal/molRuscic CBS-n
2.580.2 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = 0.03 ± 1.60 kcal/molRuscic G4
2.579.2 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 103.68 ± 1.60 kcal/molRuscic G4
2.579.4 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 103.76 ± 1.60 kcal/molRuscic CBS-n
2.381.3 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.327 ± 0.073 eVRuscic G4
2.280.1 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = 0.49 ± 1.72 kcal/molRuscic G3X


Most Influential reactions involving (H)(HH) (g, vdW)

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
0.20281.1 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 74759 ± 200 cm-1Pavanello 2009b, Matyus 2007, est unc
0.20280.7 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -55 ± 200 cm-1Pavanello 2009b, Cafiero 2001, Ruscic anh, est unc
0.09080.9 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -52 ± 300 cm-1Mielke 2002, est unc
0.09080.8 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -55 ± 300 cm-1Partridge 1993, est unc
0.07781.6 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.261 ± 0.040 eVRuscic W1RO
0.02979.5 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 103.10 ± 1.50 kcal/molRuscic W1RO
0.02980.6 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.15 ± 1.5 kcal/molTruhlar 1978, Siegbahn 1978, Liu 1973, est unc
0.02980.5 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.24 ± 1.50 kcal/molRuscic W1RO
0.02579.2 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 103.68 ± 1.60 kcal/molRuscic G4
0.02579.4 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 103.76 ± 1.60 kcal/molRuscic CBS-n
0.02580.2 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = 0.03 ± 1.60 kcal/molRuscic G4
0.02580.4 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.03 ± 1.60 kcal/molRuscic CBS-n
0.02381.3 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.327 ± 0.073 eVRuscic G4
0.02279.1 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 104.20 ± 1.72 kcal/molRuscic G3X
0.02280.1 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = 0.49 ± 1.72 kcal/molRuscic G3X
0.02281.5 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.270 ± 0.075 eVRuscic CBS-n
0.01481.2 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.342 ± 0.093 eVRuscic G3X
0.01479.3 (H)(HH) (g, vdW) → 3 H (g) ΔrH°(0 K) = 104.15 ± 2.16 kcal/molRuscic CBS-n
0.01480.3 (H)(HH) (g, vdW) → H2 (g) + H (g) ΔrH°(0 K) = -0.29 ± 2.16 kcal/molRuscic CBS-n
0.01281.4 (H)(HH) (g, vdW) → [H3]+ (g) ΔrH°(0 K) = 9.291 ± 0.099 eVRuscic CBS-n

References (for your convenience, also available in RIS and BibTex format)
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. 1.122g of the Thermochemical Network (2019); available at ATcT.anl.gov
4   J. P. Porterfield, D. H. Bross, B. Ruscic, J. H. Thorpe, T. L. Nguyen, J. H. Baraban, J. F. Stanton, J. W. Daily, and G. B. Ellison,
Thermal Decomposition of Potential Ester Biofuels, Part I: Methyl Acetate and Methyl Butanoate.
J. Chem. Phys. A 121, 4658-4677 (2017) [DOI: 10.1021/acs.jpca.7b02639] (Veronica Vaida Festschrift)
5   Y.-C. Chang, B. Xiong, D. H. Bross, B. Ruscic, and C. Y. Ng,
A Vacuum Ultraviolet laser Pulsed Field Ionization-Photoion Study of Methane (CH4): Determination of the Appearance Energy of Methylium From Methane with Unprecedented Precision and the Resulting Impact on the Bond Dissociation Energies of CH4 and CH4+.
Phys. Chem. Chem. Phys. 19, 9592-9605 (2017) [DOI: 10.1039/c6cp08200a] (part of 2017 PCCP Hot Articles collection)
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]
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]).
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.