Selected ATcT [1, 2] enthalpy of formation based on version 1.124 of the Thermochemical Network [3]

This version of ATcT results was generated by additional expansion of version 1.122x [4] to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions [5], the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm^-1 [6], as well as the study of the reversible reaction C₂H₃ + H₂ ⇌ C₂H₄ + H ⇌ C₂H₅ [7]

Oxonium

Formula: [H3O]+ (g, para)

CAS RN: 13968-08-6

ATcT ID: 13968-08-6*2

SMILES: [OH3+]

InChI: InChI=1S/H2O/h1H2/p+1

InChIKey: XLYOFNOQVPJJNP-UHFFFAOYSA-O

Hills Formula: H3O1+

2D Image:

Aliases: [H3O]+; Oxonium; Oxonium ion; Oxonium cation; Oxonium ion (1+); Hydronium; Hydronium ion; Hydronium cation; Hydronium ion (1+); Hydroxonium; Hydroxonium ion; Hydroxonium cation; Hydroxonium ion (1+); Aquahydrogen ion; Aquahydrogen cation; Aquahydrogen ion (1+); Hydrated water; Hydrogen ion hydrate; Hydrogen cation hydrate; Hydrogen ion (1+) hydrate; Protonated water; Hydrated proton; H3O+

Relative Molecular Mass: 19.02267 ± 0.00037

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
605.88	599.13	± 0.17	kJ/mol

3D Image of [H3O]+ (g, para)

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Top contributors to the provenance of Δ_fH° of [H3O]+ (g, para)

The 8 contributors listed below account for 90.2% of the provenance of Δ_fH° of [H3O]+ (g, para).

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
68.6	204.3	(H2O)2 (g) → [H3O]+ (g) + OH (g)	Δ_rH°(0 K) = 11.7556 ± 0.0020 eV	Bodi 2014
15.9	171.15	[H3O]+ (g) → H2O (g) + H+ (g)	Δ_rH°(0 K) = 683.5 ± 0.4 kJ/mol	Bodi 2014
2.6	2376.1	[CH3CH2]+ (g) + H2O (g) → [H3O]+ (g) + CH2CH2 (g)	Δ_rG°(298.15 K) = -1.8 ± 0.2 kcal/mol	Bohme 1981, 3rd Law
0.8	120.2	1/2 O2 (g) + H2 (g) → H2O (cr,l)	Δ_rH°(298.15 K) = -285.8261 ± 0.040 kJ/mol	Rossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
0.6	2376.2	[CH3CH2]+ (g) + H2O (g) → [H3O]+ (g) + CH2CH2 (g)	Δ_rG°(373 K) = -1.4 ± 0.4 kcal/mol	Leito 2010
0.5	171.8	[H3O]+ (g) → H2O (g) + H+ (g)	Δ_rH°(0 K) = 163.7 ± 0.5 kcal/mol	Peterson 1998, note unc2
0.5	1608.10	[NH4]+ (g) + H2O (g) → NH3 (g) + [H3O]+ (g)	Δ_rH°(0 K) = 38.8 ± 0.5 kcal/mol	Peterson 1998, note unc2
0.3	204.1	(H2O)2 (g) → [H3O]+ (g) + OH (g)	Δ_rH°(0 K) = 11.73 ± 0.03 eV	Ng 1977

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [H3O]+ (g, para)

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	Oxonium	[H3O]+ (g)	605.88	599.13	± 0.17	kJ/mol	19.02267 ± 0.00037	13968-08-6*0
100.0	Oxonium	[H3O]+ (g, ortho)	605.95	599.13	± 0.17	kJ/mol	19.02267 ± 0.00037	13968-08-6*1
15.0	Water dimer	(H2O)2 (g)	-491.016	-499.056	± 0.048	kJ/mol	36.03056 ± 0.00066	25655-83-8*0
14.9	Water	H2O (g)	-238.898	-241.801	± 0.025	kJ/mol	18.01528 ± 0.00033	7732-18-5*0
14.9	Oxonium	[H3O]+ (aq)		-285.796	± 0.025	kJ/mol	19.02267 ± 0.00037	13968-08-6*800
14.9	Water	H2O (cr,l)	-286.268	-285.796	± 0.025	kJ/mol	18.01528 ± 0.00033	7732-18-5*500
14.9	Water	H2O (cr, l, eq.press.)	-286.269	-285.797	± 0.025	kJ/mol	18.01528 ± 0.00033	7732-18-5*499
14.9	Water	H2O (l)		-285.796	± 0.025	kJ/mol	18.01528 ± 0.00033	7732-18-5*590
14.9	Water	H2O (l, eq.press.)		-285.797	± 0.025	kJ/mol	18.01528 ± 0.00033	7732-18-5*589
14.9	Water	H2O (g, para)	-238.898	-241.801	± 0.025	kJ/mol	18.01528 ± 0.00033	7732-18-5*2

Most Influential reactions involving [H3O]+ (g, para)

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	175.1	[H3O]+ (g, para) → [H3O]+ (g)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, Bogey 1985
0.998	176.1	[H3O]+ (g, para) → [H3O]+ (g, ortho)	Δ_rH°(0 K) = 5.10070 ± 0.00160 cm-1	Yu 2009, note unc
0.001	176.4	[H3O]+ (g, para) → [H3O]+ (g, ortho)	Δ_rH°(0 K) = 5.12055 ± 0.05 cm-1	Tang 1999, est unc
0.000	176.3	[H3O]+ (g, para) → [H3O]+ (g, ortho)	Δ_rH°(0 K) = 5.1932 ± 0.10 cm-1	Begemann 1985, est unc
0.000	176.2	[H3O]+ (g, para) → [H3O]+ (g, ortho)	Δ_rH°(0 K) = 5.20118 ± 0.10 (×1.022) cm-1	Gruebele 1987, est unc
0.000	176.5	[H3O]+ (g, para) → [H3O]+ (g, ortho)	Δ_rH°(0 K) = 5.09 ± 0.32 cm-1	Begemann 1983, note 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. 1.124 of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2022; available at ATcT.anl.gov [DOI: 10.17038/CSE/1885923]
4		Y. Ren, L. Zhou, A. Mellouki, V. Daële, M. Idir, S. S. Brown, B. Ruscic, Robert S. Paton, M. R. McGillen, and A. R. Ravishankara, Reactions of NO3 with Aromatic Aldehydes: Gas-Phase Kinetics and Insights into the Mechanism of the Reaction. Atmos. Chem. Phys. 21, 13537-13551 (2021) [DOI: 10.5194/acp2021-228]
5		B. Ruscic and D. H. Bross, Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects. Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6		J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton, Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7		T. L. Nguyen, D. H. Bross, B. Ruscic, G. B. Ellison, and J. F. Stanton, Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5. Faraday Discuss. , (Advance Article) (2022) [DOI: 10.1039/D1FD00124H]
8		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]
9		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 [8,9]).
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.