Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Oxygen atom

Formula: O (g)

CAS RN: 17778-80-2

ATcT ID: 17778-80-2*0

SMILES: [O]

InChI: InChI=1S/O

InChIKey: QVGXLLKOCUKJST-UHFFFAOYSA-N

Hills Formula: O1

2D Image:

Aliases: O; Oxygen atom; Atomic oxygen; Oxygen radical; Monooxygen; Monoxygen; O-atom; Oxygen

Relative Molecular Mass: 15.99940 ± 0.00030

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
246.844	249.229	± 0.0021	kJ/mol

3D Image of O (g)

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Top contributors to the provenance of Δ_fH° of O (g)

The 4 contributors listed below account for 96.3% of the provenance of Δ_fH° of O (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
47.7	1.4	O2 (g) → 2 O (g)	Δ_rH°(0 K) = 41269.2 ± 0.5 cm-1	Lewis 1985, note O2b
23.9	24.2	O2 (g) → O+ (g) + O- (g)	Δ_rH°(0 K) = 139321.2 ± 0.7 cm-1	Martin 1997, note O2c
14.7	1.5	O2 (g) → 2 O (g)	Δ_rH°(0 K) = 41269.6 ± 0.9 cm-1	Gibson 1991, note O2b
9.8	1.6	O2 (g) → 2 O (g)	Δ_rH°(0 K) = 41268.6 ± 1.1 cm-1	Cosby 1992, note O2b

Top 10 species with enthalpies of formation correlated to the Δ_fH° of O (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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
100.0	Oxygen atom	O (g, triplet)	246.844	249.229	± 0.0021	kJ/mol	15.99940 ± 0.00030	17778-80-2*1
99.9	Oxygen atom anion	O- (g)	105.868	108.096	± 0.0021	kJ/mol	15.99995 ± 0.00030	14337-01-0*0
99.9	Oxygen atom	O (g, singlet)	436.665	438.523	± 0.0021	kJ/mol	15.99940 ± 0.00030	17778-80-2*2
94.3	Oxygen atom cation	O+ (g)	1560.786	1562.643	± 0.0021	kJ/mol	15.99885 ± 0.00030	14581-93-2*0
16.7	Oxygen atom dication	[O]+2 (g)	4949.458	4953.000	± 0.013	kJ/mol	15.99830 ± 0.00030	14127-63-0*0
11.9	Oxygen atom trication	[O]+3 (g)	10249.929	10252.880	± 0.018	kJ/mol	15.99775 ± 0.00030	14127-64-1*0
8.4	Oxygen atom tetracation	[O]+4 (g)	17719.207	17721.064	± 0.025	kJ/mol	15.99721 ± 0.00030	14127-65-2*0
7.4	Oxidanylium	[OH]+ (g)	1293.362	1293.391	± 0.026	kJ/mol	17.00679 ± 0.00031	12259-29-9*0
6.0	Nitrogen dioxide	ONO (g)	36.875	34.068	± 0.065	kJ/mol	46.00554 ± 0.00060	10102-44-0*0
5.9	Chlorooxidanyl	ClO (g)	101.124	101.716	± 0.035	kJ/mol	51.45210 ± 0.00095	14989-30-1*0

Most Influential reactions involving O (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
1.000	20.1	O (g) → O (g, triplet)	Δ_rH°(0 K) = 0.000 ± 0.000 cm-1	triv
1.000	665.5	FFO (g, singlet) → 2 F (g) + O (g)	Δ_rH°(0 K) = 41.7 ± 5 kcal/mol	Ruscic W1RO, Ruscic CBS-n
1.000	957.4	[ClOO]+ (g) → 2 O (g) + Cl (g)	Δ_rH°(0 K) = -143.84 ± 1.50 kcal/mol	Ruscic W1RO
0.999	9048.1	OSO (g) → SO (g) + O (g)	Δ_rH°(0 K) = 45725.3 ± 0.2 cm-1	Becker 1995, Becker 1993, Braatz 1998, note unc2
0.999	21.1	O (g) → O (g, singlet)	Δ_rH°(0 K) = 15867.862 ± 0.005 cm-1	NIST Atomic Web, est unc
0.993	16.1	O (g) → O+ (g)	Δ_rH°(0 K) = 109837.02 ± 0.06 cm-1	Eriksson 1968, Moore 1970, NIST Atomic Web
0.934	44.1	OOO (g) → O2 (g) + O (g)	Δ_rH°(0 K) = 102.46 ± 0.04 kJ/mol	Taniguchi 1999, note O3d
0.927	934.1	ClO (g) → Cl (g) + O (g)	Δ_rH°(0 K) = 22182.3 ± 3 cm-1	Coxon 1976, note ClO, note ClOa
0.908	2028.1	ON(O)O (g) → O (g) + ONO (g)	Δ_rH°(0 K) = 17079 ± 15 cm-1	Johnston 1996, Davis 1993
0.860	9042.1	SO (g) → S (g) + O (g)	Δ_rH°(0 K) = 43275 ± 5 cm-1	Clerbaux 1994
0.723	1492.7	ONO (g) → NO (g) + O (g)	Δ_rH°(0 K) = 25128.56 ± 0.03 cm-1	Michalski 2004
0.625	691.7	OFO (g) → F (g) + 2 O (g)	Δ_rH°(0 K) = 11.2 ± 0.3 kcal/mol	Feller 2010
0.530	4286.6	O(CHCH) (g, singlet) → 2 C (g) + 2 H (g) + O (g)	Δ_rH°(0 K) = 437.28 ± 0.30 kcal/mol	Karton 2011
0.497	1073.8	HOCl(O)O (g) → H (g) + Cl (g) + 3 O (g)	Δ_rH°(0 K) = 257.25 ± 0.35 kcal/mol	Karton 2017
0.477	1.4	O2 (g) → 2 O (g)	Δ_rH°(0 K) = 41269.2 ± 0.5 cm-1	Lewis 1985, note O2b
0.474	17.4	O- (g) → O (g)	Δ_rH°(0 K) = 11784.675 ± 0.006 cm-1	Hotop 1999, Blondel 2005, Neumark 1985, Blondel 1995
0.459	1094.7	HOCl(O)(O)O (g) → H (g) + Cl (g) + 4 O (g)	Δ_rH°(0 K) = 313.86 ± 0.45 kcal/mol	Karton 2017
0.444	4452.9	[CH3OO]+ (g) → C (g) + 3 H (g) + 2 O (g)	Δ_rH°(0 K) = 840.85 ± 1. kJ/mol	Welch 2019, Welch 2018
0.421	1216.9	BrO (g) → Br (g) + O (g)	Δ_rH°(0 K) = 19551 ± 35 cm-1	Kim 2006
0.418	9119.5	H2OS (g) → S (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 216.31 ± 0.50 kcal/mol	Denis 2008a, 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. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
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.