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: G4

formula	sketch		Energy (kJ mol-1)		Name		difference
	A	B	calculated	experiment	A	B
C3H4			-4	-7	allene	propyne	3
C4H6			-47	-51	1,2-Butadiene	1,3-Butadiene	5
C4H6			-57	-49	Cyclobutene	1,3-Butadiene	-8
C4H6			6	3	1,2-Butadiene	1-Butyne	3
C4H6			-16	-17	1,2-Butadiene	2-Butyne	1
C3H6O			-117	-110	Oxetane	Propanal	-7
C4H8			-21505787	-33	cyclobutane	1-Butene	-21505755
C3H4O2			42	29	2-Propenoic acid	β–Propiolactone	14
C4H6S			-2	4	Thiophene, 2,5-dihydro-	Thiophene, 2,3-dihydro-	-6
C5H8			28	25	1,3-Pentadiene, (E)-	1,4-Pentadiene	2
C5H8			60	64	1,3-Pentadiene, (E)-	1,2-Pentadiene	-4
C5H8			-47	-52	1,2-Butadiene, 3-methyl-	1,3-Butadiene, 2-methyl-	5
C5H10			-9	-5	1-Butene, 2-methyl-	2-Butene, 2-methyl-	-3
C5H10			-27	-29	Cyclopropane, 1,1-dimethyl-	1-Butene, 2-methyl-	2