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: B97D3/3-21G

formula	sketch		Energy (kJ mol-1)		Name		difference
	A	B	calculated	experiment	A	B
C3H4			10	-7	allene	propyne	17
C4H6			-42	-51	1,2-Butadiene	1,3-Butadiene	10
C4H6			18	3	1,2-Butadiene	1-Butyne	15
C4H6			-67	-49	Cyclobutene	1,3-Butadiene	-18
C4H6			-118	-82	1-Methylcyclopropene	1,2-Butadiene	-36
C4H6			59	42	Methylenecyclopropane	1-Methylcyclopropene	17
C3H6O			-117	-110	Oxetane	Propanal	-7
C3H4O2			24	29	2-Propenoic acid	β–Propiolactone	-5
C4H6S			5	4	Thiophene, 2,5-dihydro-	Thiophene, 2,3-dihydro-	0
C5H8			33	25	1,3-Pentadiene, (E)-	1,4-Pentadiene	8
C5H8			54	64	1,3-Pentadiene, (E)-	1,2-Pentadiene	-10
C5H8			-41	-52	1,2-Butadiene, 3-methyl-	1,3-Butadiene, 2-methyl-	11
C5H10			-7	-5	1-Butene, 2-methyl-	2-Butene, 2-methyl-	-2
C5H10			-52	-29	Cyclopropane, 1,1-dimethyl-	1-Butene, 2-methyl-	-23