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

This version of ATcT results was generated from an expansion of version 1.122q [4, 5] to include a non-rigid rotor anharmonic oscillator (NRRAO) partition function for hydroxymethyl [6], as well as data on 42 additional species, some of which are related to soot formation mechanisms.

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Nitrogen atomN (g)[N]470.579472.442± 0.024kJ/mol14.006740 ±

Representative Geometry of N (g)

spin ON           spin OFF

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

The 9 contributors listed below account for 85.4% of the provenance of ΔfH° of N (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.

Reaction Measured Quantity Reference
28.61169.3 N2 (g) → N+ (g) N (g) ΔrH°(0 K) = 24.2880 ± 0.0009 eVTang 2005
23.21169.2 N2 (g) → N+ (g) N (g) ΔrH°(0 K) = 24.2883 ± 0.0010 eVTang 2005
23.21169.1 N2 (g) → N+ (g) N (g) ΔrH°(0 K) = 24.2888 ± 0.0010 eVTang 2005
4.61155.11 N2 (g) → 2 N (g) ΔrH°(0 K) = 78678.6 ± 18.0 cm-1Roncin 1984, note N2
2.91155.10 N2 (g) → 2 N (g) ΔrH°(0 K) = 78656.6 ± 22.7 cm-1Roncin 1984, note N2
0.81155.2 N2 (g) → 2 N (g) ΔrH°(0 K) = 78716 ± 40 (×1.044) cm-1Carroll 1965, note N2
0.61158.7 N2 (g) → 2 N (g) ΔrH°(0 K) = 941.56 ± 0.56 kJ/molHarding 2008
0.61155.1 N2 (g) → 2 N (g) ΔrH°(0 K) = 78715 ± 50 cm-1Buttenbender 1935, Gaydon 1968, note N2, as quoted by CODATA Key Vals
0.51157.10 N2 (g) → 2 N (g) ΔrH°(0 K) = 225.01 ± 0.15 kcal/molKarton 2007a

Top 10 species with enthalpies of formation correlated to the ΔfH° of N (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.

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
100.0 Nitrogen atomN (g, quartet)[N]470.579472.442± 0.024kJ/mol14.006740 ±
100.0 Nitrogen atomN (g, doublet)[N]700.555702.458± 0.024kJ/mol14.006740 ±
99.9 Nitrogen atom cationN+ (g)[N+]1872.9071875.689± 0.024kJ/mol14.006191 ±
32.8 Nitric oxideNO (g)[N]=O90.63191.135± 0.066kJ/mol30.00614 ±
32.7 Nitrosyl ion[NO]+ (g)N#[O+]984.499984.494± 0.066kJ/mol30.00559 ±
32.7 Nitrogen dioxideONO (g)O=[N]=O36.87134.064± 0.066kJ/mol46.00554 ±
31.9 Dinitrogen tetraoxideO2NNO2 (g)O=N(=O)N(=O)=O20.1810.89± 0.14kJ/mol92.0111 ±
31.7 Nitrosyl chlorideClNO (g)ClN=O54.46652.564± 0.068kJ/mol65.45884 ±
31.0 DioxohydrazineONNO (g, cis)O=NN=O172.92171.15± 0.14kJ/mol60.01228 ±
31.0 DioxohydrazineONNO (g)O=NN=O172.92171.15± 0.14kJ/mol60.01228 ±

Most Influential reactions involving N (g)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Reaction Measured Quantity Reference
1.0001171.1 N (g, quartet) → N (g) ΔrH°(0 K) = 0 ± 0 cm-1triv, NIST Atomic Web
0.6581167.1 N (g) → N+ (g) ΔrH°(0 K) = 117225.4 ± 0.1 cm-1McConkey 1968, Moore 1970
0.4972248.14 CH2NH (g) → C (g) + 3 H (g) N (g) ΔrH°(0 K) = 1733.46 ± 0.56 kJ/molGratzfeld 2017

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. 1.122r of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2021 [DOI: 10.17038/CSE/1822363]; available at
4   D. Feller, D. H. Bross, and B. Ruscic,
Enthalpy of Formation of C2H2O4 (Oxalic Acid) from High-Level Calculations and the Active Thermochemical Tables Approach.
J. Phys. Chem. A 123, 3481-3496 (2019) [DOI: 10.1021/acs.jpca.8b12329]
5   B. K. Welch, R. Dawes, D. H. Bross, and B. Ruscic,
An Automated Thermochemistry Protocol Based on Explicitly Correlated Coupled-Cluster Theory: The Methyl and Ethyl Peroxy Families.
J. Phys. Chem. A 123, 5673-5682 (2019) [DOI: 10.1021/acs.jpca.8b12329]
6   D. H. Bross, H.-G. Yu, L. B. Harding, and B. Ruscic,
Active Thermochemical Tables: The Partition Function of Hydroxymethyl (CH2OH) Revisited.
J. Phys. Chem. A 123, 4212-4231 (2019) [DOI: 10.1021/acs.jpca.9b02295]
7   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 [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.
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.