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

Comparison of experiment and theory for rCFe

Species with coordinate rCFe

Species	Name
Fe(CO)5	Iron pentacarbonyl

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

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rms differences (calculated - experiment) in Å

Methods with standard basis sets

		6-31G*	6-31+G**	6-311G*	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ
hartree fock	HF	10 0.129		5 0.138		5 0.162
density functional	BLYP	10 0.064
	B3LYP	10 0.019		10 0.014		5 0.004
	M06-2X				10 0.037
	TPSSh		10 0.014					10 0.014
	B97D3				10 0.014
		6-31G*	6-31+G**	6-311G*	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ
Moller Plesset perturbation	MP2	15 0.097		10 0.110		5 0.085
	MP2=FULL	15 0.102		10 0.112		5 0.088
	MP3		5 0.206
	B2PLYP=FULLultrafine	10 0.036					10 0.029	10 0.031
		6-31G*	6-31+G**	6-311G*	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ

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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	5 0.137		5 0.138		5 0.130	5 0.124
density functional	B3LYP	5 0.007		5 0.007		5 0.015	5 0.017
Moller Plesset perturbation	MP2	10 0.069		10 0.074		10 0.070	10 0.102

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.