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	hartrees
Energy at 0K	-75.719270
Energy at 298.15K	-75.716241
HF Energy	-75.484520
Nuclear repulsion energy	14.434377

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.660
C2	0.000	0.000	-0.660

	C1	C2
C1		1.3194
C2	1.3194

Number	Element	Mulliken	CHELPG	AIM	ESP
1	C	0.000
2	C	0.000

	x	y	z
x	0.000	0.000	0.000
y	0.000	0.000	0.000
z	0.000	0.000	0.000

All results from a given calculation for C₂ (Carbon diatomic)

using model chemistry: ROMP2/TZVP

States and conformations

State 1 (¹Σ_g⁺)

State 2 (³Π_u)

State 3 (³Σ_g^-)

	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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<r²>	12.809
(<r²>)^1/2	3.579

All results from a given calculation for C2 (Carbon diatomic)

using model chemistry: ROMP2/TZVP

States and conformations

State 1 (1Σg+)

State 2 (3Πu)

State 3 (3Σg-)

All results from a given calculation for C₂ (Carbon diatomic)

State 1 (¹Σ_g⁺)

State 2 (³Π_u)

State 3 (³Σ_g^-)