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 Al₂⁺ (aluminum diatomic cation)

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
composite	G1	s1e
	G2MP2	s1e
	G2	s1e
	G3	s1e
	G3B3	s1e
	G3MP2	s1e
	G4	s1e
	CBS-Q	s1e

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Methods with standard basis sets

		3-21G	3-21G*	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-pVTZ	daug-cc-pVTZ
hartree fock	HF			s1ov						s1ov				s1ov
	ROHF			s1ov
density functional	BLYP			s1ov
	B3LYP									s1ov
	B3LYPultrafine												s1ov
	M06-2X		s1ov	s1ov					s1ov
	PBE1PBE			s1ov
	HSEh1PBE	s1ov		s1ov	s1ov							s1ov
	TPSSh			s1ov	s1ov			s1ov				s1ov
	wB97X-D		s1ov	s1ov	s1ov		s1ov			s1ov	s1ov	s1ov	s1ov
	B97D3	s1ov		s1ov	s1ov		s1ov		s1ov	s1ov		s1ov	s1ov	s1ov
		3-21G	3-21G*	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-pVTZ	daug-cc-pVTZ
Moller Plesset perturbation	MP2			s1ov		s1ov				s1ov
	MP3				s1o
	MP3=FULL			s1ov	s1ov
	MP4											s1ov
	B2PLYP			s1ov								s1ov
	B2PLYP=FULLultrafine			s1ov							s1ov	s1ov	s1ov
		3-21G	3-21G*	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-pVTZ	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
density functional	B3LYP									s1ov
	PBEPBE									s1ov
Moller Plesset perturbation	MP2									s1ov

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Single point energy calculations (select basis sets)

		cc-pVTZ	aug-cc-pVTZ
Moller Plesset perturbation	MP2FC// B3LYP/6-31G*	s1e
	MP2FC// MP2FC/6-31G*		s1e
Coupled Cluster	CCSD(T)// B3LYP/6-31G*	s1e
	CCSD(T)// MP2FC/6-31G*		s1e

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.