Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Relative enthalpies of isomers - Comparison of 0K enthalpies (kJ mol^-1)

Isomers of C₄H₄O₂

index	Species	CAS number	Name	Relative experimental enthalpy (kJ mol-1)	sketch
a	C4H4O2	497234	2(5H)-Furanone
b	C4H4O2	674828	2-Oxetanone, 4-methylene-