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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IV.D.4. (XII.A.2.)

Comparison of experiment and theory for rBrI

Species with coordinate rBrI

Species	Name
IBr	Iodine monobromide

The small prefix is the number of bonds with completed calculations.
Click on an entry for a histogram of the difference distribution.

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rms differences (calculated - experiment) in Å

Methods with predefined basis sets

semi-empirical	PM3	1 0.092

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rms differences (calculated - experiment) in Å

Methods with standard basis sets

		3-21G	3-21G*	6-31G*	6-311G*
hartree fock	HF	1 0.172	1 0.008		1 0.023
density functional	LSDA	1 0.168	1 0.015		1 0.015
	BLYP	1 0.242	1 0.058		1 0.099
	B1B95	1 0.176	1 0.005		1 0.021
	B3LYP	1 0.210	1 0.030		1 0.063
	B3LYPultrafine	1 0.210	1 0.031		1 0.063
	B3PW91	1 0.189	1 0.008		1 0.035
	mPW1PW91	1 0.181	1 0.002		1 0.027
	M06-2X	1 0.177	2 0.006		1 0.024
	PBEPBE	1 0.211	1 0.022		1 0.057
	PBEPBEultrafine	1 0.211	1 0.023		1 0.057
	PBE1PBE	1 0.180	1 0.001		1 0.025
	HSEh1PBE	1 0.186	1 0.004		1 0.032
	wB97X-D		1 0.023
	B97D3	1 0.223
		3-21G	3-21G*	6-31G*	6-311G*
Moller Plesset perturbation	MP2	1 0.221	1 0.021	1 0.060	2 0.041
	MP2=FULL	1 0.222	1 0.020		1 0.038
	MP4	1 0.248	1 0.039		1 0.058
	B2PLYP	1 0.211	1 0.025		1 0.050
Configuration interaction	CID	1 0.237	1 0.025		1 0.031
	CISD	1 0.241	1 0.026		1 0.032
		3-21G	3-21G*	6-31G*	6-311G*
Quadratic configuration interaction	QCISD	1 0.253	1 0.036		1 0.053
	QCISD(T)	1 0.257	1 0.042		1 0.062
Coupled Cluster	CCD	1 0.247	1 0.034		1 0.049
	CCSD	1 0.253	1 0.036		1 0.053
	CCSD(T)	1 0.257	1 0.042		1 0.062
	CCSD(T)=FULL	1 0.258	1 0.041		1 0.064
		3-21G	3-21G*	6-31G*	6-311G*

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rms differences (calculated - experiment) in Å

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	1 0.107		1 0.107		1 0.160	1 0.126	1 0.003		2 0.018
	ROHF							1 0.003		1 0.005
density functional	LSDA	1 0.147		1 0.147		1 0.191	1 0.161	1 0.009		1 0.016
	BLYP	1 0.195		1 0.195		1 0.240	1 0.209	1 0.071		1 0.066
	B1B95	1 0.136		1 0.136		1 0.183	1 0.150	1 0.002		1 0.006
	B3LYP	1 0.161		1 0.161		1 0.208	1 0.176	1 0.037		2 0.029
	B3LYPultrafine	1 0.161		1 0.161		1 0.208	1 0.176	1 0.037		1 0.031
	B3PW91	1 0.140		1 0.140		1 0.187	1 0.154	1 0.010		1 0.005
	mPW1PW91	1 0.131		1 0.131		1 0.179	1 0.145	1 0.002		1 0.003
	M06-2X	1 0.127		1 0.127		1 0.173	1 0.143	1 0.001		1 0.002
	PBEPBE	1 0.162		1 0.162		1 0.207	1 0.176	1 0.031		2 0.023
	PBEPBEultrafine	1 0.162		1 0.162		1 0.207	1 0.176	1 0.031		1 0.025
	PBE1PBE	1 0.129		1 0.129		1 0.177	1 0.143	1 0.000		1 0.005
	HSEh1PBE	1 0.133		1 0.133		1 0.181	1 0.148	1 0.006		1 0.001
	TPSSh							1 0.015		1 0.010
	wB97X-D							1 0.002		1 0.003
	B97D3							1 0.049		1 0.043
Moller Plesset perturbation	MP2	1 0.175		1 0.175		1 0.217	1 0.189	1 0.007		2 0.023
	MP2=FULL	1 0.175		1 0.175		1 0.217	1 0.189	1 0.009		1 0.017
	ROMP2							1 0.008		1 0.014
	MP3							1 0.010		1 0.007
	MP3=FULL							1 0.008		1 0.005
	MP4	1 0.208		1 0.208		1 0.255	1 0.227	1 0.014		1 0.011
	MP4=FULL							1 0.013		1 0.008
	B2PLYP	1 0.162		1 0.162		1 0.209	1 0.178	1 0.019		1 0.014
	B2PLYP=FULL							1 0.018		1 0.013
	B2PLYP=FULLultrafine							1 0.018		1 0.013
Configuration interaction	CID	1 0.200		1 0.200		1 0.248	1 0.220	1 0.006		1 0.016
	CISD	1 0.205		1 0.205		1 0.254	1 0.225	1 0.005		1 0.016
Quadratic configuration interaction	QCISD	1 0.213		1 0.213		1 0.262	1 0.234	1 0.010		1 0.006
	QCISD(T)	1 0.217		1 0.217		1 0.266	1 0.238	1 0.018		1 0.016
	QCISD(T)=FULL							1 0.016		1 0.012
Coupled Cluster	CCD	1 0.207		1 0.207		1 0.255	1 0.227	1 0.007		1 0.003
	CCSD	1 0.213		1 0.213		1 0.262	1 0.233	1 0.010		1 0.006
	CCSD=FULL							1 0.008		1 0.003
	CCSD(T)	1 0.217		1 0.217		1 0.266	1 0.238	1 0.018		1 0.015
	CCSD(T)=FULL	1 0.217		1 0.217		1 0.266	1 0.238	1 0.016		1 0.012

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.