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: BLYP/6-311G**

formula	sketch		Energy (kJ mol-1)		Name		difference
	A	B	calculated	experiment	A	B
C3H4			12	-7	allene	propyne	19
C4H6			-72	-49	Cyclobutene	1,3-Butadiene	-23
C4H6			-40	-51	1,2-Butadiene	1,3-Butadiene	11
C4H6			24	3	1,2-Butadiene	1-Butyne	21
C4H6			-4	-17	1,2-Butadiene	2-Butyne	12
C4H6			-96	-82	1-Methylcyclopropene	1,2-Butadiene	-14
C4H6			46	42	Methylenecyclopropane	1-Methylcyclopropene	4
C3H6O			-128	-110	Oxetane	Propanal	-18
C4H8			-45	-33	cyclobutane	1-Butene	-12
C3H4O2			46	29	2-Propenoic acid	β–Propiolactone	18
C5H8			-38	-52	1,2-Butadiene, 3-methyl-	1,3-Butadiene, 2-methyl-	14
C5H8			37	25	1,3-Pentadiene, (E)-	1,4-Pentadiene	12
C5H8			58	64	1,3-Pentadiene, (E)-	1,2-Pentadiene	-6
C5H10			-11	-5	1-Butene, 2-methyl-	2-Butene, 2-methyl-	-6
C5H10			-42	-29	Cyclopropane, 1,1-dimethyl-	1-Butene, 2-methyl-	-13