Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
	Home All data for one species Geometry Experimental Experimental Geometries Same bond/angle many molecules Internal Coordinates by type Bond angles Calculated Calculated geometry Rotational constant Moments of inertia Products of moments of inertia BSE Bond lengths Show me a calculated geometry Comparisons Bonds, angles Rotational Constants Products of moments of inertia Point group Bad Calculations Bad moment of inertia Tutorials and Explanations Angle formulas Vibrations Experimental Vibrational frequencies Calculated Frequencies Scale factors Reactions Entropies Ions List Ions Energy Calculated Ionization Energy Compare Ionzation energy Electron Affinity Calculated Electron affinity Compare Electron affinity Proton Affinity Calculated Proton affinity Compare Proton affinity Ionization changes point group Experimental One molecule all properties One property a few molecules Enthalpy of formation Entropy Integrated Heat Capacity Heat Capacity Rotational Constants Vibrational Frequencies Dipole moment Ionization Energy Polarizability Quadrupole Point Groups Geometry Experimental Geometries Internal Coordinates by type Bond angles Rotational Constants Point Groups Diatomic bond lengths Vibrations Vibrational frequencies Diatomic Triatomics Energy Atomization Energy Internal Rotation Electrostatics Dipole Quadrupole Polarizability Reference Data Reference states Spin Splittings Molecules with good enthalpy Enthalpy at 0 Kelvin Calculated Energy Optimized Energy Energy 298K Minimum conformation Hydrogen bonds H bond with counterpoise Reaction Reaction Energy 0K Reaction Energy 298K Internal Rotation Barriers to internal rotation Rotational barrier and dipole Rotational Barrier 2 molecules Orbital HOMO LUMO gap HOMO Orbital Energies Nuclear repulsion energy Correlation Full vs Frozen core energies Partial correlation energies Ion Calculated Ionization Energy Vertical ionization Energy Calculated Electron affinity Calculated Proton affinity Atom charge differences Excited State Singlet triplet gap Electronic state Transition state Basis Set Extrapolation BSE energy BSE Bond lengths Geometry Calculated geometry AIM bond orders One type of bond Rotation Rotational constant Products of moments of inertia Moments of inertia Inertial defects Second moments Point group State symmetry <r2> Sorted by r2 Z-matrix Bad Calculations Bad moment of inertia Bad Calculated Bond Lengths Bad point group Worst molecules Vibrations Frequencies Animated vibrations Anharmonic Zero point energy (ZPE) Scale Factors Scale factors Scale factor uncertainty Calculate a scale factor Why scale vibrations Set scaling factors Bad Calculations Bad Vib. HF vs MP2 Bad vib. Calc. vs exp. 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Calc. vs exp. Bad Vib. HF vs MP2 Bad scale factors Low excited states Oddities NaCN Is not linear FAQ Help Units Choose Units Energy Bond length Rotational Constant Moment of Inertia Dipole and Quadrupole Polarizability Explanations Hartree cm-1 Debye Credits Just show me Show me a calculated geometry Summary Using older interface Limit Basis sets Method options List Recent molecules Choose a few Molecules Number of atoms By heavy atoms Diatomics InChI Deuterated Dimers Geometry Point group Point group count Bonds types Isodesmic reactions Bad point group Multiple conformers, states Vibrations Big anharmonicity Energy Enthalpy at 0 Kelvin Similar molecules Similar Isomers Cis/trans Tautomers Multiple conformers, states Ions, Dipoles, etc. List Ions Ionization changes point group Dipole Quadrupole Polarizability Proton Affinities Index of CCCBDB Feedback Error form Wants
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Bonds
A-H bonds					C-A bonds											Other
	C-H		Si-H			CC any		CN any		CO any		CS any		CX any			N-O
	N-H		P-H			C-C		C-N		C-O		C-S		C-F			N-S
	O-H		S-H			C=C		C=N		C=O		C=S		C-Cl			C-P
						C#C		C#N						C-Br			S-O

Organic Groups
	alkane		C-O-H alcohol		r-N=O		OOH peroxy		3 membered ring
	alkene		C-O-C ether		r-NO2 nitro		NH2 amine		4 membered ring
	alkyne		COOH acid		r-ONO nitrite				5 membered ring
	diene		C(O)OC ester		r-ONO2 nitrate		RCH3		6 membered ring
			CC(O)C ketone		C(O)N amide		R2CH2		aromatic
			CC(O)H aldehyde				R3CH		bicyclic
			COC epoxide				R4C		phenyl
			Chalcogen (O, S, Se, Te)		Halogen (F, Cl, Br, I)
substituted methanes, etc.
	methanes		ethanes		propanes		butanes		pentanes
			ethenes						hexanes

Elements
Must contain these elements	any H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D	any H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D	any H He Li He Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D	any H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D
Must NOT contain these elements	none H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D	none H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D	none H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D	none H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ti Cu Zn Ge As Se Br Te I D
only first row (H thru Ne)
contains a metal

Atom Count
Total number of atoms = > < any 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Heavy (non-hydrogen) atoms = > < any 0 1 2 3 4 5 6

Radicals		Ions		Hydrogen-bonded		Salts
	Must be a radical (unpaired electrons)		Must be an ion (charged)		Hydrogen-bonded dimer		Must be a salt
	Exclude all radicals		Exclude all ions				Exclude all salts

Atmospheric		Refrigerants
	Atmospheric molecules		CFC		HCFC		HBFC		HFC		PFC

Point Group
C1	Cs	Ci	C∞v	D∞h	Td	Oh	Kh
C2	C3
C2v	C3v	C4v
C2h	C3h
D2	D3
D2d	D3d	D4d	D5d
D2h	D3h		D5h	D6h	D7h

Experimental Uncertainty in Enthalpy of formation (kJ/mol)
Less or equal to no limit 10 8 6 5 4 3 2 1 0.5 kJ/mol	More than no limit 10 8 6 5 4 3 2 1 0.5 kJ/mol

G2 Set (no ions, no excited states)
	G2-1 set (53 species)
	G2/97 set extended (146 species)

Constraints from experimental vibrational frequencies
	experimental frequencies are present
	species that are good for determining scaling factors