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

This version of ATcT results was partially described in Ruscic et al. [4], and was also used for the initial development of high-accuracy ANLn composite electronic structure methods [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
AmmoniaNH3 (g)N-38.562-45.554± 0.030kJ/mol17.03056 ±
0.00022		7664-41-7*0

Representative Geometry of NH3 (g)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of NH3 (g)

The 8 contributors listed below account for 90.0% of the provenance of ΔfH° of NH3 (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
48.81149.1 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.885 ± 0.010 kcal/molLarson 1923, Vanderzee 1972
24.91148.5 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.875 ± 0.014 kcal/molSchulz 1966, Vanderzee 1972
9.51148.4 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.910 ± 0.015 (×1.509) kcal/molLarson 1924, Vanderzee 1972
3.41149.8 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrG°(635 K) = 20.084 ± 0.157 kJ/molSchulz 1966, 3rd Law
1.01149.3 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrG°(686 K) = 6.165 ± 0.068 kcal/molLarson 1923, 3rd Law, est unc
1.01208.1 N2 (g) + 3 H2O (cr,l) + 2 H+ (aq) → 3/2 O2 (g) + 2 [NH4]+ (aq) ΔrH°(298.15 K) = 141.292 ± 0.119 kcal/molVanderzee 1972c
0.61148.3 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(823 K) = -53.88 ± 0.19 (×1.957) kJ/molWittig 1959
0.61146.7 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(776.15 K) = -12.656 ± 0.089 kcal/molHaber 1915

Top 10 species with enthalpies of formation correlated to the ΔfH° of NH3 (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
99.9 Aminium[NH3]+ (g)[NH3+]944.275937.320± 0.030kJ/mol17.03001 ±
0.00022		19496-55-0*0
51.7 AmmoniaNH3 (aq, undissoc)N-80.886± 0.053kJ/mol17.03056 ±
0.00022		7664-41-7*1000
49.5 Ammonium[NH4]+ (aq)[NH4+]-133.077± 0.056kJ/mol18.03795 ±
0.00029		14798-03-9*800
47.5 Ammonium hydroxideNH4OH (aq, undissoc)[NH4+].[OH-]-366.715± 0.062kJ/mol35.04584 ±
0.00047		1336-21-6*1000
44.1 Ammonium chloride(NH4)Cl (cr)[NH4+].[Cl-]-311.724-314.886± 0.063kJ/mol53.49120 ±
0.00095		12125-02-9*510
17.4 Aminylium[NH2]+ (g)[NH2+]1266.551264.47± 0.12kJ/mol16.02207 ±
0.00016		15194-15-7*0
17.4 AmidogenNH2 (g)[NH2]188.91186.02± 0.12kJ/mol16.02262 ±
0.00016		13770-40-6*0
16.0 Ammonium bromide(NH4)Br (cr)[NH4+].[Br-]-253.56-270.14± 0.17kJ/mol97.9425 ±
0.0010		12124-97-9*510
14.3 Ammonium[NH4]+ (g)[NH4+]643.05631.74± 0.21kJ/mol18.03795 ±
0.00029		14798-03-9*0
9.0 Ammonium nitrate(NH4)NO3 (cr,l)[NH4+].O=[N+]([O-])[O-]-350.28-365.25± 0.19kJ/mol80.04344 ±
0.00095		6484-52-2*500

Most Influential reactions involving NH3 (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
0.9991139.3 NH3 (g) → [NH3]+ (g) ΔrH°(0 K) = 82158.751 ± 0.032 cm-1Seiler 2003
0.7113941.1 C6H6 (g) + [NH2]- (g) → [C6H5]- (g) + NH3 (g) ΔrG°(300 K) = -3.557 ± 0.047 kcal/molDavico 1995
0.6281817.1 [C2H3]- (g) + NH3 (g) → [NH2]- (g) + C2H4 (g) ΔrG°(298.15 K) = -4.54 ± 0.24 kcal/molErvin 1990
0.5801912.2 [NH2]- (g) + CH3NH2 (g) → [CH3NH]- (g) + NH3 (g) ΔrG°(296 K) = -0.51 ± 0.20 kcal/molMacKay 1976, note unc2
0.5281199.1 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.448 ± 0.015 kcal/molVanderzee 1972
0.4881149.1 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.885 ± 0.010 kcal/molLarson 1923, Vanderzee 1972
0.4732206.8 CO (g) + [NH4]+ (g) → [HCO]+ (g) + NH3 (g) ΔrH°(0 K) = 259.89 ± 0.3 kJ/molCzako 2008
0.4631153.8 [NH4]+ (g) → NH3 (g) + H+ (g) ΔrH°(0 K) = 846.40 ± 0.3 kJ/molCzako 2008
0.3711142.9 [NH3]- (g) → NH3 (g) ΔrH°(0 K) = -1.41 ± 0.04 eVPuzzarini 2008
0.3401306.1 NH2OH (g, trans) + H2O (g) → H2O2 (g) + NH3 (g) ΔrH°(0 K) = 24.9 ± 0.2 kcal/molFeller 2003, est unc
0.3391305.1 NH2OH (g, trans) + H2 (g) → H2O (g) + NH3 (g) ΔrH°(0 K) = -58.4 ± 0.2 kcal/molFeller 2003, est unc
0.3271170.1 NH3 (g) → [NH2]+ (g) + H (g) ΔrH°(0 K) = 15.765 ± 0.002 eVSong 2001a, note unc2
0.2763219.6 (CH3)2NH (g) + NH3 (g) → 2 CH3NH2 (g) ΔrH°(298.15 K) = 4.68 ± 0.40 kcal/molIssoire 1960, as quoted by Cox 1970
0.2673223.6 (CH3)3N (g) + NH3 (g) → (CH3)2NH (g) + CH3NH2 (g) ΔrH°(298.15 K) = 7.82 ± 0.40 kcal/molIssoire 1960, as quoted by Cox 1970
0.2491148.5 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.875 ± 0.014 kcal/molSchulz 1966, Vanderzee 1972
0.2371142.8 [NH3]- (g) → NH3 (g) ΔrH°(0 K) = -1.349 ± 0.050 eVRuscic W1RO
0.2161219.7 H2NNH2 (g) + H2 (g) → 2 NH3 (g) ΔrH°(0 K) = -45.18 ± 0.25 kcal/molKarton 2008, Karton 2006
0.1543941.3 C6H6 (g) + [NH2]- (g) → [C6H5]- (g) + NH3 (g) ΔrG°(300 K) = -3.618 ± 0.101 kcal/molDavico 1995
0.1494100.1 (CH2COOH)2(NH3)2 (cr) → (CH2COOH)2(NH3) (cr) + NH3 (g) ΔrH°(298.15 K) = 16.0 ± 0.5 kcal/molBiltz 1928, Biltz 1928a, Vanderzee 1972c, est unc
0.1321199.2 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/molStavaley 1971, Vanderzee 1972, as quoted by CODATA Key Vals
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. 1.122 of the Thermochemical Network (2016); available at ATcT.anl.gov
4   B. Ruscic,
Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry.
J. Phys. Chem. A 119, 7810-7837 (2015) [DOI: 10.1021/acs.jpca.5b01346]
5   S. J. Klippenstein, L. B. Harding, and B. Ruscic,
Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.
J. Phys. Chem. A 121, 6580-6602 (2017) [DOI: 10.1021/acs.jpca.7b05945]
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.