Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Nitrogen atom

Formula: N (g, quartet)

CAS RN: 17778-88-0

ATcT ID: 17778-88-0*1

SMILES: [N]

InChI: InChI=1S/N

InChIKey: QJGQUHMNIGDVPM-UHFFFAOYSA-N

Hills Formula: N1

2D Image:

Aliases: N; Nitrogen atom; Nitrogen; Atomic nitrogen; Nitrogen radical; Mononitrogen; N-atom

Relative Molecular Mass: 14.006740 ± 0.000070

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
470.583	472.445	± 0.022	kJ/mol

3D Image of N (g, quartet)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of N (g, quartet)

The 19 contributors listed below account for 90.2% of the provenance of Δ_fH° of N (g, quartet).

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
24.5	1436.3	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2880 ± 0.0009 eV	Tang 2005
19.8	1436.2	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2883 ± 0.0010 eV	Tang 2005
19.8	1436.1	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2888 ± 0.0010 eV	Tang 2005
8.2	1413.11	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.14 ± 0.15 kJ/mol	Thorpe 2021
6.3	1437.2	[N2]+ (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 70248 ± 12 (×1.189) cm-1	Hertzler 1992, Douglas 1952, Hertzler 1990, Janin 1957, est unc
3.9	1420.10	N2 (g) → 2 N (g, doublet)	Δ_rH°(0 K) = 117127.5 ± 18.0 cm-1	Roncin 1984, note N2
2.5	1420.9	N2 (g) → 2 N (g, doublet)	Δ_rH°(0 K) = 117105.5 ± 22.7 cm-1	Roncin 1984, note N2
0.7	1410.2	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 78716 ± 40 (×1.022) cm-1	Carroll 1965, note N2
0.5	1413.7	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.56 ± 0.56 kJ/mol	Harding 2008
0.5	1410.1	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 78715 ± 50 cm-1	Buttenbender 1935, Gaydon 1968, note N2, as quoted by CODATA Key Vals
0.4	1412.4	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 225.01 ± 0.15 kcal/mol	Karton 2007a, Karton 2006, Karton 2011
0.3	1413.4	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.61 ± 0.70 kJ/mol	Bomble 2006
0.3	1413.5	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.74 ± 0.70 kJ/mol	Harding 2008
0.3	1413.6	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.09 ± 0.74 kJ/mol	Harding 2008
0.3	1413.3	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.14 ± 0.75 kJ/mol	Bomble 2006
0.3	1413.1	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.07 ± 0.75 kJ/mol	Tajti 2004, est unc
0.2	1413.2	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.78 ± 0.80 kJ/mol	Bomble 2006
0.2	1414.1	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 225.0 ± 0.2 kcal/mol	Feller 2006a
0.2	1414.6	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 224.99 ± 0.20 kcal/mol	Feller 2014

Top 10 species with enthalpies of formation correlated to the Δ_fH° of N (g, quartet)

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	Nitrogen atom	N (g)	470.583	472.445	± 0.022	kJ/mol	14.006740 ± 0.000070	17778-88-0*0
100.0	Nitrogen atom	N (g, doublet)	700.559	702.462	± 0.022	kJ/mol	14.006740 ± 0.000070	17778-88-0*2
99.9	Nitrogen atom cation	N+ (g)	1872.911	1875.692	± 0.022	kJ/mol	14.006191 ± 0.000070	14158-23-7*0
93.0	Nitrogen atom dication	[N]+2 (g)	4728.998	4731.826	± 0.024	kJ/mol	14.005643 ± 0.000070	17439-59-7*0
31.1	Nitric oxide	NO (g)	90.627	91.131	± 0.064	kJ/mol	30.00614 ± 0.00031	10102-43-9*0
31.0	Nitrosyl ion	[NO]+ (g)	984.494	984.489	± 0.064	kJ/mol	30.00559 ± 0.00031	14452-93-8*0
31.0	Nitrogen dioxide	ONO (g)	36.866	34.059	± 0.064	kJ/mol	46.00554 ± 0.00060	10102-44-0*0
30.2	Dinitrogen tetraoxide	O2NNO2 (g)	20.17	10.88	± 0.14	kJ/mol	92.0111 ± 0.0012	10544-72-6*0
30.0	Nitrosyl chloride	ClNO (g)	54.461	52.559	± 0.067	kJ/mol	65.45884 ± 0.00095	2696-92-6*0
29.3	Dioxohydrazine	ONNO (g, cis)	172.91	171.14	± 0.14	kJ/mol	60.01228 ± 0.00062	16824-89-8*2

Most Influential reactions involving N (g, quartet)

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	1438.1	N (g, quartet) → N (g)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, NIST Atomic Web
1.000	1439.1	N (g, quartet) → N (g, doublet)	Δ_rH°(0 K) = 19224.464 ± 0.005 cm-1	Moore 1975, Sansonetti 2005
0.113	5712.2	HCNN (g, doublet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 133.10 ± 2.0 kJ/mol	Klippenstein 2017
0.099	5679.2	HNCN (g, doublet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 277.37 ± 2.0 kJ/mol	Klippenstein 2017
0.055	5809.5	NCHN (g, quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 4.21 ± 1.50 kcal/mol	Ruscic W1RO
0.049	5809.4	NCHN (g, quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 4.75 ± 1.60 kcal/mol	Ruscic CBS-n
0.049	5809.2	NCHN (g, quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 4.78 ± 1.60 kcal/mol	Ruscic G4
0.042	5809.1	NCHN (g, quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 5.45 ± 1.72 kcal/mol	Ruscic G3X
0.041	5713.5	HCNN (g, c-quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = -12.49 ± 1.50 kcal/mol	Ruscic W1RO
0.038	5682.5	HNCN (g, t-quartet) → HNC (g) + N (g, quartet)	Δ_rH°(0 K) = 1.90 ± 1.50 kcal/mol	Ruscic W1RO
0.036	5713.2	HCNN (g, c-quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = -12.69 ± 1.60 kcal/mol	Ruscic G4
0.036	5713.4	HCNN (g, c-quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = -11.57 ± 1.60 kcal/mol	Ruscic CBS-n
0.033	5682.2	HNCN (g, t-quartet) → HNC (g) + N (g, quartet)	Δ_rH°(0 K) = 2.43 ± 1.60 kcal/mol	Ruscic G4
0.033	5682.4	HNCN (g, t-quartet) → HNC (g) + N (g, quartet)	Δ_rH°(0 K) = 3.19 ± 1.60 kcal/mol	Ruscic CBS-n
0.031	5713.1	HCNN (g, c-quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = -12.39 ± 1.72 kcal/mol	Ruscic G3X
0.028	5682.1	HNCN (g, t-quartet) → HNC (g) + N (g, quartet)	Δ_rH°(0 K) = 2.90 ± 1.72 kcal/mol	Ruscic G3X
0.026	5809.3	NCHN (g, quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 5.96 ± 2.16 kcal/mol	Ruscic CBS-n
0.023	5940.1	CH (g, quartet) + N2 (g) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = -15.28 ± 0.8 kcal/mol	Harding 2008a, est unc
0.020	5713.3	HCNN (g, c-quartet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = -11.86 ± 2.16 kcal/mol	Ruscic CBS-n
0.018	5682.3	HNCN (g, t-quartet) → HNC (g) + N (g, quartet)	Δ_rH°(0 K) = 2.21 ± 2.16 kcal/mol	Ruscic CBS-n

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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument, Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
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.