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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III.F.2.

Completed calculations for Si₂ (Silicon diatomic)

Methods and basis sets for which an energy has been calculated. "e" indicates just an energy has been calculated. "o" indicates an optimized geometry. "v" indicates vibrational frequencies. "s" followed by a number indicates completed calculations for different states (for example s1ov). "c" followed by a number indicates completed calculations for different conformations (for example c2ov).
See the Calculated Energies page (section III.A.1) for more calculated properties.

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Methods with predefined basis sets

semi-empirical	PM3	s1ov s2ov
composite	G1	s1e s2e
	G2MP2	s1e s2e
	G2	s1e s2e
	G3	s1e s2e
	G3B3	s1e s2e
	G3MP2	s1e
	G4	s1e s2e
	CBS-Q	s1e s2e

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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	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	cc-pV(T+d)Z	daug-cc-pVTZ
hartree fock	HF	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s1ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s2ov	s2ov		s1ov s2ov
density functional	LSDA	s1ov s2ov	s2ov	s2ov	s1ov s2ov	s1ov s2ov	s2ov	s2ov	s1ov s2ov	s2ov	s2ov			s2ov	s2ov		s2ov	s2ov
	BLYP	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s2ov	s1ov		s1ov s2ov	s1ov s2ov
	B1B95	s2ov		s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov			s2ov	s2ov	s2ov	s2ov	s2ov	s2ov
	B3LYP	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov		s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s2ov	s2ov
	B3LYPultrafine					s2ov						s1ov						s1ov s2ov
	B3PW91	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s1ov		s1ov s2ov	s1ov s2ov
	mPW1PW91	s2ov	s1ov s2ov	s2ov	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s2ov	s1ov		s1ov s2ov	s1ov s2ov
	M06-2X			s1ov s2ov		s1ov s2ov						s1ov s2ov
	PBEPBE	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s2ov	s1ov		s2ov	s2ov	s2ov	s2ov	s2ov	s2ov
	PBE1PBE					s1ov s2ov
	HSEh1PBE		s1ov s2ov			s1ov s2ov		s1ov s2ov							s1ov s2ov
	TPSSh					s1ov s2ov		s1ov s2ov			s1ov s2ov				s1ov s2ov
	wB97X-D			s1ov s2ov		s1ov s2ov		s1ov s2ov		s1ov s2ov			s1ov s2ov	s1ov s2ov	s1ov s2ov			s1ov s2ov
	B97D3		s1ov s2o			s1ov s2ov		s1ov s2ov		s1ov s2o		s1ov s2ov	s1ov s2ov		s1ov			s1ov s2ov			s1ov s2ov
		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	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	cc-pV(T+d)Z	daug-cc-pVTZ
Moller Plesset perturbation	MP2	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s1ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov	s1ov
	MP2=FULL	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s2ov	s1ov		s1ov s2ov	s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov		s1ov
	PMP2					s1o		s1o
	MP3					s2ov		s1o s2o						s1ov
	MP3=FULL					s1ov s2ov		s1ov s2ov
	MP4		s1ov s2ov	s1ov	s1ov	s1ov s2ov		s1ov	s1ov	s2ov		s1ov			s1ov		s1ov
	B2PLYP					s1ov s2ov									s1ov s2ov
	B2PLYP=FULLultrafine					s1ov s2ov								s1ov s2ov	s1ov s2ov			s1ov s2ov
Configuration interaction	CID		s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov		s1ov	s1ov s2ov			s1ov		s1ov	s1ov
	CISD		s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov	s1ov	s2ov			s1ov		s1ov	s1ov
		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	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	cc-pV(T+d)Z	daug-cc-pVTZ
Quadratic configuration interaction	QCISD		s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s1ov s2ov	s2ov	s2ov	s1ov		s1ov s2ov	s1ov s2ov		s1ov
	QCISD(T)					s1ov s2ov		s1ov	s1ov			s1ov		s1ov s2ov	s1ov s2ov		s1ov s2ov	s2ov
Coupled Cluster	CCD		s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s1ov s2ov	s2ov	s2ov	s1ov		s1ov s2ov	s1ov s2ov		s1ov s2ov	s2ov
	CCSD					s1ov s2ov		s1ov	s1ov			s1ov		s1ov	s1ov		s1ov
	CCSD(T)					s1ov s2ov	s1ov		s1ov					s1ov s2ov	s1ov s2ov	s2ov	s1ov s2ov	s2ov
	CCSD(T)=FULL					s2ov										s2ov
		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	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	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	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov			s1ov s2ov
density functional	B1B95		s1ov
	B3LYP	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov			s1ov s2ov
	PBEPBE									s1ov s2ov
Moller Plesset perturbation	MP2	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov	s1ov s2ov			s1ov s2ov

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Single point energy calculations (select basis sets)

		6-311+G(3df,2p)	cc-pVDZ	cc-pVTZ	aug-cc-pVDZ	aug-cc-pVTZ
Moller Plesset perturbation	MP2FC// HF/6-31G*	s1e	s1e	s1e	s1e	s1e
	MP2FC// B3LYP/6-31G*	s1e	s1e	s1e	s1e	s1e
	MP2FC// MP2FC/6-31G*			s1e	s1e	s2e
Coupled Cluster	CCSD// HF/6-31G*	s1e	s1e		s1e	s1e
	CCSD(T)// HF/6-31G*	s1e	s1e	s1e	s1e	s1e
	CCSD// B3LYP/6-31G*	s1e	s1e	s1e	s1e
	CCSD(T)// B3LYP/6-31G*		s1e	s1e	s1e
	CCSD// MP2FC/6-31G*				s1e	s2e
	CCSD(T)// MP2FC/6-31G*	s1e			s1e	s2e

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.