Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Tautomer energy comparison

using model chemistry: LSDA/cc-pV(T+d)Z

formula	sketch		Energy (kJ mol-1)		Name		difference
	A	B	calculated	experiment	A	B
C4H6			-5	-17	1,2-Butadiene	2-Butyne	12
C4H6			-65	-82	1-Methylcyclopropene	1,2-Butadiene	17
C4H6			50	42	Methylenecyclopropane	1-Methylcyclopropene	9
C5H8			40	25	1,3-Pentadiene, (E)-	1,4-Pentadiene	15
C5H8			55	64	1,3-Pentadiene, (E)-	1,2-Pentadiene	-9
C5H10			-4	-29	Cyclopropane, 1,1-dimethyl-	1-Butene, 2-methyl-	25
C5H10			-16	-5	1-Butene, 2-methyl-	2-Butene, 2-methyl-	-10