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State	Conformation	minimum conformation	conformer description	state description
1	1	yes	D*H	¹Σ_g⁺
2	1	yes	D*H	³Π_u

	hartrees
Energy at 0K	-75.227671
Energy at 298.15K	-75.224644
HF Energy	-74.954264
Nuclear repulsion energy	15.110570

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.630
C2	0.000	0.000	-0.630

	C1	C2
C1		1.2607
C2	1.2607

	hartrees
Energy at 0K	-75.216408
Energy at 298.15K	-75.213377
HF Energy	-75.039776
Nuclear repulsion energy	14.214796

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

using model chemistry: QCISD/3-21G

States and conformations

State 1 (¹Σ_g⁺)

State 2 (³Π_u)

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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	C1	C2
C1		1.3402
C2	1.3402

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

using model chemistry: QCISD/3-21G

States and conformations

State 1 (1Σg+)

State 2 (3Πu)

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

State 1 (¹Σ_g⁺)

State 2 (³Π_u)