National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 22	May 2022
NIST Standard Reference Database 101

I	Introduction
II	Experimental data
III	Calculated data
IV	Data comparisons
V	Cost comparisons
VI	Input and output files
VII	Tutorials and Units
VIII	Links to other sites
IX	Feedback
X	Older CCCBDB versions
XII	Geometries
XIII	Vibrations
XIV	Reaction data
XV	Entropy data
XVI	Bibliographic data
XVII	Ion data
XVIII	Bad calculations
XIX	Index of properties
XX	H-bond dimers
XXI	Oddities

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Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

IV.A.4. (XIV.F.)

Relative enthalpies of isomers - Comparison of 0K enthalpies (kJ mol^-1)

Isomers of C₆H₈

2015 06 30 15:39

index	Species	CAS number	Name	Relative experimental enthalpy (kJ mol-1)	sketch
a	C6H8	592574	1,3-Cyclohexadiene	0.0
b	C6H8	628411	1,4-Cyclohexadiene	2.5
c	C6H8	694019	Bicyclo[3.1.0]hex-2-ene
d	C6H8	821078	(E)-hexa-1,3,5-triene
e	C6H8	822413	Bicyclo[2.1.1]hex-2-ene
f	C6H8	930267	3-Methylenecyclopentene
g	C6H8	2612466	(Z)-hexa-1,3,5-triene
h	C6H8	30830207	Bicyclo[2.2.0]hex-1(4)-ene
i	C6H8	59660649	(Z)-hexa-2,3,4-triene
j	C6H8	59660650	(E)-hexa-2,3,4-triene

The calculated enthalpies include the calculated and scaled vibrational zero-point energy.

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Methods with predefined basis sets

composite	G1	NC NC NC NC NC
	G2MP2	NC NC NC NC NC
	G3B3	NC NC NC NC NC NC

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Methods with standard basis sets

		STO-3G	3-21G	3-21G*	6-31G	6-31G*	6-31G**	6-31+G**	6-311G*	6-311G**	6-31G(2df,p)	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ	aug-cc-pVDZ	aug-cc-pVTZ	cc-pV(T+d)Z	daug-cc-pVTZ
hartree fock	HF	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC	0.0 a -6.9 b 61.2 c 159.0 e -1.8 f 301.9 h
density functional	LSDA	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC
	BLYP	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC
	B1B95	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC	NC NC NC NC NC NC NC NC NC
	B3LYP	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC
	B3LYPultrafine					NC NC NC NC NC NC NC NC NC		NC NC NC							NC NC NC NC		NC NC NC NC NC NC NC NC NC
	B3PW91	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC
	mPW1PW91	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC
	M06-2X			0.0 a 2.4 b 52.7 c 80.1 d 110.1 e 6.8 f 83.8 g 295.4 h 153.7 i 153.5 j		NC NC NC NC NC NC NC NC NC
	PBEPBE	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC
	PBEPBEultrafine					NC NC NC NC NC NC NC NC NC
	PBE1PBE					NC NC NC NC NC NC NC NC NC
	HSEh1PBE		NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC							NC NC NC NC NC NC NC NC NC
	TPSSh					NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC				NC NC NC NC NC NC NC NC NC
	wB97X-D			NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC
	B97D3		NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC		0.0 a 2.4 b 59.1 c 29.0 d 150.8 e -0.4 f 36.3 g 280.1 h 107.3 i 107.2 j	0.0 a 2.5 b 63.1 c 29.9 d 153.4 e 0.2 f 37.1 g 284.1 h 107.7 i 107.6 j		NC NC NC NC NC NC NC NC NC		NC NC NC NC NC NC NC NC NC
		STO-3G	3-21G	3-21G*	6-31G	6-31G*	6-31G**	6-31+G**	6-311G*	6-311G**	6-31G(2df,p)	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ	aug-cc-pVDZ	aug-cc-pVTZ	cc-pV(T+d)Z	daug-cc-pVTZ
Moller Plesset perturbation	MP2	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC	NC NC NC NC NC NC NC	NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC		NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC	NC NC	NC NC
	MP2=FULL		NC NC	NC NC	NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC	NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC				NC NC NC	NC NC NC
	MP3					NC NC NC NC NC NC NC NC NC
	MP3=FULL					NC NC NC NC NC NC NC NC		NC NC NC NC NC NC
	B2PLYP					NC NC NC NC NC NC NC NC NC									NC NC NC NC NC NC NC NC NC
	B2PLYP=FULLultrafine					NC NC NC NC NC NC
Configuration interaction	CID		NC NC	NC NC		NC NC NC			NC NC
	CISD		NC NC	NC NC		NC NC NC			NC NC
		STO-3G	3-21G	3-21G*	6-31G	6-31G*	6-31G**	6-31+G**	6-311G*	6-311G**	6-31G(2df,p)	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ	aug-cc-pVDZ	aug-cc-pVTZ	cc-pV(T+d)Z	daug-cc-pVTZ
Quadratic configuration interaction	QCISD		NC NC NC	NC NC NC	NC NC	NC NC NC	NC NC NC NC NC	NC NC NC NC	NC NC NC	NC NC				NC NC
Coupled Cluster	CCD		NC NC NC	NC NC NC	NC NC	NC NC NC NC	NC NC NC	NC NC NC	NC NC NC					NC NC
		STO-3G	3-21G	3-21G*	6-31G	6-31G*	6-31G**	6-31+G**	6-311G*	6-311G**	6-31G(2df,p)	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ	aug-cc-pVDZ	aug-cc-pVTZ	cc-pV(T+d)Z	daug-cc-pVTZ

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Methods with effective core potentials (select basis sets)

		CEP-31G	CEP-31G*	CEP-121G	CEP-121G*	LANL2DZ	SDD	cc-pVTZ-PP	aug-cc-pVTZ-PP	Def2TZVPP
hartree fock	HF	-97963.8 b -97895.1 c -97919.2 d -97813.5 e -97965.0 f -97911.0 g -97644.0 h -97781.5 i -97781.5 j	-98215.5 b -98169.2 c -98155.0 d -98094.5 e -98214.4 f -98146.4 g -97934.8 h -98024.1 i -98024.4 j	-98010.8 b -97933.5 c -97964.8 d -97847.3 e -98010.1 f -97956.4 g -97684.7 h -97858.0 i -97858.2 j	-98278.6 b -98216.1 c -98223.1 d -98132.1 e -98274.8 f -98214.2 g -97984.7 h -98121.1 i -98121.2 j	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC
density functional	B1B95	NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC
	B3LYP	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC NC
	PBEPBE									NC NC NC NC NC NC NC NC NC
Moller Plesset perturbation	MP2	-99207.5 b -99152.4 c -99169.6 d -99088.8 e -99219.1 f -99163.5 g -98926.6 h -99053.2 j	NC NC NC NC NC NC -99865.7 h -99919.6 i -99920.5 j	-99391.2 b -99335.1 c -99354.9 d -99268.6 e -99400.3 f -99351.2 g -99101.8 h -99257.8 i	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC	NC NC NC NC NC NC NC NC NC			NC NC NC NC NC NC NC NC

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Single point energy calculations (select basis sets)

		cc-pVDZ	cc-pVTZ	aug-cc-pVDZ	aug-cc-pVTZ	cc-pV(T+d)Z
Moller Plesset perturbation	MP2FC// HF/6-31G*	NC NC NC NC NC	NC NC NC NC NC			NC NC NC NC NC
	MP2FC// B3LYP/6-31G*	NC NC NC NC NC
	MP2FC// MP2FC/6-31G*			NC NC NC NC NC	NC NC NC NC NC
Coupled Cluster	CCSD// MP2FC/6-31G*				NC NC NC NC NC
	CCSD(T)// MP2FC/6-31G*				NC NC NC NC NC

NC = not calculated

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For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.
gaw refers to the group additivity method implemeted in the NIST Chemistry Webbook.

See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.