Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Helium cation

Formula: He+ (g)

CAS RN: 14234-48-1

ATcT ID: 14234-48-1*0

SMILES: [He+]

InChI: InChI=1S/He/q+1

InChIKey: QLNXTEZOQCZJBA-UHFFFAOYSA-N

Hills Formula: He1+

2D Image:

Aliases: He+; Helium cation; Helium ion (1+); Helium atom cation; Helium atom ion (1+); Atomic helium cation; Atomic helium ion (1+)

Relative Molecular Mass: 4.0020534 ± 0.0000020

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
2372.322	2372.322	± 0.000	kJ/mol

3D Image of He+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of He+ (g)

The 3 contributors listed below account for 93.6% of the provenance of Δ_fH° of He+ (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
75.5	9297.1	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.66637 ± 0.00040 cm-1	Kandula 2010, note unc, Tiesinga 2021
9.6	9297.10	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.6667 ± 0.0028 cm-1	Korobov 2001, note unc
8.3	9297.2	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.6672 ± 0.0030 cm-1	Eikema 1997, note unc

Top 10 species with enthalpies of formation correlated to the Δ_fH° of He+ (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	Image	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
77.6	Helium dication	[He]+2 (g)		7622.839	7622.839	± 0.000	kJ/mol	4.0015048 ± 0.0000020	12587-46-1*0

Most Influential reactions involving He+ (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
0.755	9297.1	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.66637 ± 0.00040 cm-1	Kandula 2010, note unc, Tiesinga 2021
0.499	9315.13	[He2]+ (g) → He (g) + He+ (g)	Δ_rH°(0 K) = 19116.116 ± 2 cm-1	Tung 2012, est unc
0.499	9315.14	[He2]+ (g) → He (g) + He+ (g)	Δ_rH°(0 K) = 19116.128 ± 2 cm-1	Cencek 2000, Tung 2012, est unc
0.497	9298.5	He+ (g) → [He]+2 (g)	Δ_rH°(0 K) = 438908.8782 ± 0.0002 cm-1	Erickson 1977, note std dev
0.497	9298.7	He+ (g) → [He]+2 (g)	Δ_rH°(0 K) = 438908.8785 ± 0.0004 cm-1	Johnson 1985, note std dev, Tiesinga 2021
0.096	9297.10	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.6667 ± 0.0028 cm-1	Korobov 2001, note unc
0.084	9297.2	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.6672 ± 0.0030 cm-1	Eikema 1997, note unc
0.035	9297.3	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.6712 ± 0.0032 (×1.445) cm-1	Bergeson 1998, note unc
0.021	9297.11	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.6668 ± 0.0060 cm-1	Drake 1998, note unc
0.005	9297.12	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.655 ± 0.01 (×1.164) cm-1	Drake 1988, est unc
0.005	9298.3	He+ (g) → [He]+2 (g)	Δ_rH°(0 K) = 438908.877 ± 0.010 cm-1	Garcia 1965
0.001	9297.9	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.674 ± 0.025 cm-1	Dalgarno 1960
0.000	9297.7	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.687 ± 0.05 cm-1	Pekeris 1959, est unc
0.000	9297.8	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.67 ± 0.05 cm-1	Pekeris 1958, est unc
0.000	9297.5	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.76 ± 0.02 (×4.757) cm-1	Seaton 1966a, note unc
0.000	9315.8	[He2]+ (g) → He (g) + He+ (g)	Δ_rH°(0 K) = 54.44 ± 0.50 kcal/mol	Gurtubay 2006, Huber 1979, est unc
0.000	9296.1	He (g, triplet) → He+ (g)	Δ_rH°(0 K) = 38454.8274 ± 0.2 cm-1	Accad 1971, est unc
0.000	9297.4	He (g) → He+ (g)	Δ_rH°(0 K) = 198310.81 ± 0.10 (×1.445) cm-1	Martin 1970
0.000	9315.12	[He2]+ (g) → He (g) + He+ (g)	Δ_rH°(0 K) = 2.343 ± 0.030 eV	Gadea 1996, Huber 1979, est unc
0.000	9315.10	[He2]+ (g) → He (g) + He+ (g)	Δ_rH°(0 K) = 2.365 ± 0.030 eV	Huber 1979, Liu 1971, 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 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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
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.