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].
|
Helium |
Formula: He (g, triplet) |
CAS RN: 7440-59-7 |
ATcT ID: 7440-59-7*1 |
SMILES: [He] |
InChI: InChI=1S/He |
InChIKey: SWQJXJOGLNCZEY-UHFFFAOYSA-N |
Hills Formula: He1 |
2D Image: |
|
Aliases: He; Helium; Helium atom; Atomic helium |
Relative Molecular Mass: 4.0026020 ± 0.0000020 |
ΔfH°(0 K) | ΔfH°(298.15 K) | Uncertainty | Units |
---|
1912.302 | 1912.302 | ± 0.000 | kJ/mol |
|
3D Image of He (g, triplet) |
|
spin ON spin OFF |
|
Top contributors to the provenance of ΔfH° of He (g, triplet)The 3 contributors listed below account for 99.9% of the provenance of ΔfH° of He (g, triplet).
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.
|
|
Top 10 species with enthalpies of formation correlated to the ΔfH° of He (g, triplet) |
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 | 81.6 | Helium | He (g, singlet) | | -0.000 | -0.000 | ± 0.000 | kJ/mol | 4.0026020 ± 0.0000020 | 7440-59-7*2 | 64.4 | Helium anion | He- (g, 1s.2s.2p 4P) | | 1904.822 | 1904.822 | ± 0.000 | kJ/mol | 4.0031506 ± 0.0000020 | 14452-58-5*3 |
|
Most Influential reactions involving He (g, triplet)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 | 0.999 | 9054.1 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.07752848 ± 0.00000018 eV | Wang 2014, note unc | 0.500 | 9047.2 | He (g, singlet) → He (g, triplet)  | ΔrH°(0 K) = 159855.9745 ± 0.0005 cm-1 | Sansonetti 2005, est unc | 0.500 | 9047.1 | He (g, singlet) → He (g, triplet)  | ΔrH°(0 K) = 159855.9743297 ± 0.0000020 cm-1 | NIST Atomic Web, Morton 2006 | 0.108 | 9055.1 | He- (g, 2p3 4S3/2) → He (g, triplet)  | ΔrH°(0 K) = -39.5132 ± 0.010 eV | Turbiner 2013, Bylicki 1996, est unc, Tech 1971 | 0.043 | 9068.2 | [He2]- (g, quartet 4Pig) → He (g, triplet) + He (g)  | ΔrH°(0 K) = 1.954 ± 0.080 (×1.164) eV | Michels 1986, est unc | 0.037 | 9068.1 | [He2]- (g, quartet 4Pig) → He (g, triplet) + He (g)  | ΔrH°(0 K) = 2.005 ± 0.100 eV | Michels 1984, est unc | 0.017 | 9055.2 | He- (g, 2p3 4S3/2) → He (g, triplet)  | ΔrH°(0 K) = -39.517 ± 0.025 eV | Turbiner 2013, Bylicki 1996, Trabert 1992, Walter 1994, Tech 1971 | 0.004 | 9055.3 | He- (g, 2p3 4S3/2) → He (g, triplet)  | ΔrH°(0 K) = -39.537 ± 0.050 eV | Nicolaides 1981, est unc, Tech 1971 | 0.004 | 9055.4 | He- (g, 2p3 4S3/2) → He (g, triplet)  | ΔrH°(0 K) = -39.526 ± 0.050 eV | Chung 1979, est unc, Tech 1971 | 0.000 | 9054.3 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.077516 ± 0.000012 (×1.044) eV | Kristensen 1997a, note unc | 0.000 | 9054.2 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.077518 ± 0.000022 eV | Kristensen 1997a, note unc | 0.000 | 9048.1 | He (g, triplet) → He+ (g)  | ΔrH°(0 K) = 38454.8274 ± 0.2 cm-1 | Accad 1971, est unc | 0.000 | 9054.4 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.07767 ± 0.00012 (×1.189) eV | Walter 1994 | 0.000 | 9054.5 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.0775 ± 0.0008 eV | Peterson 1985 | 0.000 | 9054.7 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.07751 ± 0.0008 eV | Bunge 1984, Turbiner 2013, Bylicki 1996, note unc | 0.000 | 9054.6 | He- (g, 1s.2s.2p 4P) → He (g, triplet)  | ΔrH°(0 K) = 0.0774 ± 0.003 eV | Bunge 1979 |
|
|
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. 1.156 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.
|