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].

Silicon carbide

Formula: SiC (cr, alpha-hex)

CAS RN: 409-21-2

ATcT ID: 409-21-2*501

SMILES: [Si]=[C]

InChI: InChI=1S/CSi/c1-2

InChIKey: HBMJWWWQQXIZIP-UHFFFAOYSA-N

Hills Formula: C1Si1

2D Image:

Aliases: SiC; Silicon carbide; Silanyliumylidynemethanide

Relative Molecular Mass: 40.09620 ± 0.00085

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-70.6	-71.6	± 1.5	kJ/mol

Top contributors to the provenance of Δ_fH° of SiC (cr, alpha-hex)

The 8 contributors listed below account for 91.1% of the provenance of Δ_fH° of SiC (cr, alpha-hex).

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
58.8	8478.1	SiC (cr, alpha-hex) + 4 F2 (g) → SiF4 (g) + CF4 (g)	Δ_rH°(298.15 K) = -591.77 ± 0.38 kcal/mol	Greenberg 1970
12.8	8483.1	SiC (cr, beta-cubic) → SiC (cr, alpha-hex)	Δ_rH°(298.15 K) = 0.26 ± 0.63 kcal/mol	Greenberg 1970
5.0	8491.1	Si (cr,l) + 2 F2 (g) → SiF4 (g)	Δ_rH°(298.15 K) = -385.98 ± 0.19 kcal/mol	Wise 1963, Wise 1963, Wise 1962
4.2	8484.1	SiC (cr, alpha-hex) → Si (g) + C (graphite)	Δ_rG°(2140 K) = 47.5 ± 1.5 kcal/mol	Davis 1961a, 3rd Law
3.7	8479.1	SiC (cr, beta-cubic) + 4 F2 (g) → SiF4 (g) + CF4 (g)	Δ_rH°(298.15 K) = -591.51 ± 0.34 kcal/mol	Greenberg 1970
3.3	8484.2	SiC (cr, alpha-hex) → Si (g) + C (graphite)	Δ_rG°(2212 K) = 43.37 ± 1.7 kcal/mol	Drowart 1958, 3rd Law
1.6	546.1	SiF4 (g) + 2 H2O (cr,l) → Si (cr,l) + O2 (g) + 4 HF (aq, 5 H2O)	Δ_rH°(298.15 K) = 899.77 ± 1.20 kJ/mol	Paulechka 2020, Vorobev 1960, Hummel 1959, Johnson 1987, Good 1964, Good 1964, Johnson 1973
1.4	8485.2	2 SiC (cr, alpha-hex) → Si2 (g) + 2 C (graphite)	Δ_rH°(2000 K) = 165 ± 5 (×1.044) kcal/mol	Drowart 1958, 3rd Law

Top 10 species with enthalpies of formation correlated to the Δ_fH° of SiC (cr, alpha-hex)

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	Silicon carbide	SiC (cr,l)	-70.6	-71.6	± 1.5	kJ/mol	40.09620 ± 0.00085	409-21-2*500
34.8	Tetrafluorosilane	SiF4 (g)	-1608.76	-1614.27	± 0.52	kJ/mol	104.07911 ± 0.00030	7783-61-1*0
34.7	Silicon carbide	SiC (cr, beta-cubic)	-71.9	-72.9	± 1.4	kJ/mol	40.09620 ± 0.00085	409-21-2*502
24.8	Dioxosilane	SiO2 (cr, quartz)	-906.77	-911.75	± 0.63	kJ/mol	60.08430 ± 0.00067	7631-86-9*505
24.8	Dioxosilane	SiO2 (cr,l)	-906.77	-911.75	± 0.63	kJ/mol	60.08430 ± 0.00067	7631-86-9*500
24.6	Fluorosilylidyne	SiF (g, quartet)	297.19	298.41	± 0.62	kJ/mol	47.08390 ± 0.00030	11128-24-8*2
24.6	Fluorosilylidyne	SiF (g)	-60.32	-58.48	± 0.62	kJ/mol	47.08390 ± 0.00030	11128-24-8*0
24.6	Fluorosilylidyne	SiF (g, doublet)	-60.32	-58.48	± 0.62	kJ/mol	47.08390 ± 0.00030	11128-24-8*1
24.5	Silicon	Si (g)	450.34	454.68	± 0.56	kJ/mol	28.08550 ± 0.00030	7440-21-3*0
24.5	Silicon anion	Si- (g)	316.28	319.26	± 0.56	kJ/mol	28.08605 ± 0.00030	14337-02-1*0

Most Influential reactions involving SiC (cr, alpha-hex)

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	8482.1	SiC (cr, alpha-hex) → SiC (cr,l)	Δ_rH°(0 K) = 0 ± 0 cm-1	Gurvich TPIS
0.696	8478.1	SiC (cr, alpha-hex) + 4 F2 (g) → SiF4 (g) + CF4 (g)	Δ_rH°(298.15 K) = -591.77 ± 0.38 kcal/mol	Greenberg 1970
0.377	8483.1	SiC (cr, beta-cubic) → SiC (cr, alpha-hex)	Δ_rH°(298.15 K) = 0.26 ± 0.63 kcal/mol	Greenberg 1970
0.056	8486.1	SiC (cr, alpha-hex) → SiC (g)	Δ_rG°(2248 K) = 84.12 ± 2.6 kcal/mol	Drowart 1958, 3rd Law
0.049	8484.1	SiC (cr, alpha-hex) → Si (g) + C (graphite)	Δ_rG°(2140 K) = 47.5 ± 1.5 kcal/mol	Davis 1961a, 3rd Law
0.038	8484.2	SiC (cr, alpha-hex) → Si (g) + C (graphite)	Δ_rG°(2212 K) = 43.37 ± 1.7 kcal/mol	Drowart 1958, 3rd Law
0.018	8485.2	2 SiC (cr, alpha-hex) → Si2 (g) + 2 C (graphite)	Δ_rH°(2000 K) = 165 ± 5 (×1.044) kcal/mol	Drowart 1958, 3rd Law

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.