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 rNaK

Species with coordinate rNaK

Species	Name
NaK	Sodium Potassium

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	PM6	1 0.258
composite	G2	1 0.061
	G3	1 0.063
	G3B3	1 0.042
	G4	1 0.005
	CBS-Q	1 0.061

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rms differences (calculated - experiment) in Å

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
hartree fock	HF	1 0.740	1 0.118	1 0.126	1 0.096	1 0.099	1 0.099	1 0.103	1 0.101	1 0.101	1 0.099		1 0.113
density functional	LSDA	1 0.790	1 0.704	1 0.704	1 0.188	1 0.184		1 0.185	1 0.195	1 0.195	1 0.203		1 0.158
	BLYP	1 0.738	1 0.080	1 0.110	1 0.069	2 0.044	1 0.058	1 0.058	1 0.072	1 0.072	1 0.074		1 0.043
	B1B95	1 0.764		1 0.040	1 0.079	1 0.076	1 0.076	1 0.076	1 0.073	1 0.073	1 0.081		1 0.049
	B3LYP	1 0.753	1 0.088	1 0.115	1 0.085	1 0.078	1 0.078	1 0.078	1 0.087	1 0.087	1 0.089		1 0.062
	B3LYPultrafine					1 0.079
	B3PW91	1 0.747	1 0.003	1 0.007	1 0.030	1 0.029	1 0.029	1 0.029	1 0.034	1 0.034	1 0.036		1 0.008
	mPW1PW91	1 0.751	1 0.000	1 0.003	1 0.029	1 0.028	1 0.028	1 0.028	1 0.032	1 0.032	1 0.034		1 0.008
	M06-2X	1 0.780	1 0.128	2 0.159	1 0.198	1 0.200	1 0.200	1 0.200	1 0.200		1 0.202	1 0.203	1 0.175
	PBEPBE	1 0.745	1 0.045	1 0.052	1 0.052	1 0.048	1 0.048	1 0.048	1 0.055	1 0.055	1 0.058		1 0.027
	HSEh1PBE	1 0.756	1 0.026	1 0.028	1 0.038	1 0.037	1 0.037	1 0.037	1 0.043	1 0.043	1 0.044		1 0.017
	TPSSh					1 0.020		1 0.020			1 0.016
	wB97X-D			1 0.020		1 0.053		1 0.053		1 0.053			1 0.033	1 0.053
	B97D3		1 0.030			1 0.021		1 0.021		1 0.017		1 0.016
		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
Moller Plesset perturbation	MP2	1 0.742	1 0.117	1 0.108	1 0.091	2 0.014	1 0.019	1 0.015	2 0.044	1 0.057	1 0.145		1 0.115
	MP2=FULL	1 0.758	1 0.112	1 0.079	1 0.089	1 0.032	1 0.032	1 0.029	1 0.086	1 0.086	1 0.174		1 0.084
	MP3					1 0.035		1 0.013
	MP3=FULL					1 0.020		1 0.018
	MP4		1 0.106			1 0.034				1 0.055
Configuration interaction	CID		1 0.105	1 0.092	1 0.084	1 0.029			1 0.040
	CISD		1 0.119	1 0.097	1 0.098	1 0.022			1 0.040
		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
Quadratic configuration interaction	QCISD		1 0.119	1 0.097	1 0.099	1 0.017	1 0.017	1 0.012	1 0.031	1 0.031	1 0.138		1 0.119
	QCISD(T)					1 0.017							1 0.119
Coupled Cluster	CCD		1 0.105	1 0.091	1 0.084	2 0.021	1 0.029	1 0.025	1 0.045	1 0.045	1 0.130		1 0.100
	CCSD					1 0.018
	CCSD(T)					1 0.017							1 0.119
	CCSD(T)=FULL					1 0.030							1 0.100
		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

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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 0.154		1 0.110		1 0.124	1 0.094			1 0.067
density functional	B3LYP	1 0.118		1 0.079		1 0.000	1 0.081			1 0.037
	PBEPBE									1 0.020
Moller Plesset perturbation	MP2	1 0.191		1 0.131		1 0.137	1 0.082			1 0.054

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.