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].

Helium anion

Formula: He- (g, 2p3 4S3/2)

CAS RN: 14452-58-5

ATcT ID: 14452-58-5*4

SMILES: [He-]

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

InChIKey: GQCTUJCUOFABIY-UHFFFAOYSA-N

Hills Formula: He1-

2D Image:

Aliases: He-; Helium anion; Helium ion (1-); Helium atom anion; Helium atom ion (1-); Atomic helium anion; Atomic helium ion (1-)

Relative Molecular Mass: 4.0031506 ± 0.0000020

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
5724.96	5724.96	± 0.32	kJ/mol

3D Image of He- (g, 2p3 4S3/2)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of He- (g, 2p3 4S3/2)

The 3 contributors listed below account for 97.4% of the provenance of Δ_fH° of He- (g, 2p3 4S3/2).

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
43.2	9257.1	He- (g, 1s.2s.2p 4P) → He- (g, 2p3 4S3/2)	Δ_rH°(0 K) = 39.59308 ± 0.005 eV	Salas 2014, est unc
43.2	9257.2	He- (g, 1s.2s.2p 4P) → He- (g, 2p3 4S3/2)	Δ_rH°(0 K) = 39.59307 ± 0.005 eV	Turbiner 2013, Bylicki 1996, Salas 2014, est unc
10.8	9256.1	He- (g, 2p3 4S3/2) → He (g, triplet)	Δ_rH°(0 K) = -39.5132 ± 0.010 eV	Turbiner 2013, Bylicki 1996, est unc, Tech 1971

Most Influential reactions involving He- (g, 2p3 4S3/2)

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
0.432	9257.2	He- (g, 1s.2s.2p 4P) → He- (g, 2p3 4S3/2)	Δ_rH°(0 K) = 39.59307 ± 0.005 eV	Turbiner 2013, Bylicki 1996, Salas 2014, est unc
0.432	9257.1	He- (g, 1s.2s.2p 4P) → He- (g, 2p3 4S3/2)	Δ_rH°(0 K) = 39.59308 ± 0.005 eV	Salas 2014, est unc
0.108	9256.1	He- (g, 2p3 4S3/2) → He (g, triplet)	Δ_rH°(0 K) = -39.5132 ± 0.010 eV	Turbiner 2013, Bylicki 1996, est unc, Tech 1971
0.017	9256.2	He- (g, 2p3 4S3/2) → He (g, triplet)	Δ_rH°(0 K) = -39.517 ± 0.025 eV	Turbiner 2013, Bylicki 1996, Trabert 1992, Walter 1994, Tech 1971
0.004	9256.3	He- (g, 2p3 4S3/2) → He (g, triplet)	Δ_rH°(0 K) = -39.537 ± 0.050 eV	Nicolaides 1981, est unc, Tech 1971
0.004	9256.4	He- (g, 2p3 4S3/2) → He (g, triplet)	Δ_rH°(0 K) = -39.526 ± 0.050 eV	Chung 1979, est unc, Tech 1971

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. 1.172 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.