Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Experimental data for CH₂^- (methylene anion)

Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)

Property	Value	Uncertainty	units	Reference	Comment
Hfg(298.15K)	391.20	1.60	kJ mol-1	2005Rus/Bog:573
Hfg(0K)	390.70	1.60	kJ mol-1	2005Rus/Bog:573
Entropy (298.15K)	194.44		J K-1 mol-1	2005Rus/Bog:573
Integrated Heat Capacity (0 to 298.15K)	10.03		kJ mol-1	2005Rus/Bog:573
Heat Capacity (298.15K)	35.13		J K-1 mol-1	2005Rus/Bog:573

Information can also be found for this species in the NIST Chemistry Webbook

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