Selected ATcT [1, 2] enthalpy of formation based on version 1.122p of the Thermochemical Network [3]

This version of ATcT results was generated from an expansion of version 1.122o [4] to include an updated enthalpy of formation for Hydrazine. [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
Argon dimerAr2 (g)[Ar][Ar]-1.013-6.347± 0.0051kJ/mol79.8960 ±
0.0020		12595-59-4*0

Representative Geometry of Ar2 (g)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of Ar2 (g)

The 2 contributors listed below account for 90.5% of the provenance of ΔfH° of Ar2 (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
72.45435.2 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.75 ± 0.5 cm-1Aziz 1993, Colbourn 1976a, Herman 1988, est unc
18.15435.1 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.5 ± 1 cm-1Herman 1988

Top 10 species with enthalpies of formation correlated to the ΔfH° of Ar2 (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    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
30.4 Argon dimer cation[Ar2]+ (g)[Ar][Ar+]1393.7601391.173± 0.018kJ/mol79.8955 ±
0.0020		17596-58-6*0

Most Influential reactions involving Ar2 (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
0.9005436.1 Ar2 (g) → [Ar2]+ (g) ΔrH°(0 K) = 116594.2 ± 1.4 cm-1Rupper 2002, note unc
0.7245435.2 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.75 ± 0.5 cm-1Aziz 1993, Colbourn 1976a, Herman 1988, est unc
0.1815435.1 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.5 ± 1 cm-1Herman 1988
0.0495436.2 Ar2 (g) → [Ar2]+ (g) ΔrH°(0 K) = 116591.1 ± 6.0 cm-1Signorell 1998
0.0495436.3 Ar2 (g) → [Ar2]+ (g) ΔrH°(0 K) = 116593.5 ± 6.0 cm-1Signorell 1997
0.0455435.3 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.75 ± 2 cm-1Colbourn 1976a, est unc
0.0145435.4 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.0 ± 3.5 cm-1LeRoy 1972, Tanaka 1970
0.0075435.6 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 83.4 ± 5 cm-1Dehmer 1978, est unc
0.0075435.5 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.3 ± 5 cm-1Maitland 1971, Tanaka 1970, est unc
0.0075435.8 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 84.02 ± 5 cm-1Barker 1971, Colbourn 1976a, est unc
0.0075435.7 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 83.25 ± 5 cm-1Parson 1972, Colbourn 1976a, est unc
0.0025435.10 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 87 ± 8 cm-1Cavallini 1970, est unc
0.0025435.9 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 82.5 ± 8 cm-1Present 1973, Tanaka 1970, est unc
0.0005436.4 Ar2 (g) → [Ar2]+ (g) ΔrH°(0 K) = 14.450 ± 0.005 (×1.164) eVHall 1995
0.0005435.12 Ar2 (g) → 2 Ar (g) ΔrH°(0 K) = 0.238 ± 0.10 kcal/molZhou 2014, Colbourn 1976a, 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 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. 1.122p of the Thermochemical Network (2020); available at ATcT.anl.gov
4   P. B. Changala, T. L. Nguyen, J. H. Baraban, G. B. Ellison, J. F. Stanton, D. H. Bross, and B. Ruscic,
Active Thermochemical Tables: The Adiabatic Ionization Energy of Hydrogen Peroxide.
J. Phys. Chem. A 121, 8799-8806 (2017) [DOI: 10.1021/acs.jpca.7b06221] (highlighted on the journal cover)
5   D. Feller, D. H. Bross, and B. Ruscic,
Enthalpy of Formation of N2H4 (Hydrazine) Revisited.
J. Phys. Chem. A 121, 6187-6198 (2017) [DOI: 10.1021/acs.jpca.7b06017]
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]
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]).
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.