Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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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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All data (experiment and calculated) in the CCCBDB for C₄H₆O₂ (Crotonic Acid)

Property		Experiment	Calculated	Comparison
Energies Entropies	Enthalpy 298.15K
	Enthalpy 0K
	Energy 0K		305
	Energy 298.15K		295
	Atomization Enthalpy 298.15K		0
	Atomization Enthalpy 0K		0
	Entropy (298.15K)	x	0	x
	Entropy at any temperature		0
	Integrated Heat Capacity		0
	Heat Capacity (Cp)		0
	Nuclear Repulsion Energy		301
	HOMO-LUMO Energies		301
	Barriers to Internal Rotation		0
Geometries	Cartesians		301
	Internal Coordinates		300
	Products of moments of inertia		291
	Rotational Constants		297
	Point Group		305
Vibrations	Vibrational Frequencies		294
	Vibrational Intensities		285
	Zero-point energies		294
	Vibrational scaling factors
	Anharmonic frequencies and constants
	Raman frequencies and intensities		0
Electronic States	Electronic states	x	0
Electrostatics	Atom charges		199
	Dipole		261
	Quadrupole		231
	Polarizability		232
Other results	Spin		0
	Number of basis functions		25
	Conformations		1