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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	-10.942846
Energy at 298.15K	-10.939819
HF Energy	-10.625736
Nuclear repulsion energy	6.637278

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.638
C2	0.000	0.000	-0.638

	C1	C2
C1		1.2756
C2	1.2756

	hartrees
Energy at 0K	-10.936085
Energy at 298.15K	-10.933055
HF Energy	-10.718463
Nuclear repulsion energy	6.344522

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

using model chemistry: MP2/CEP-121G*

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		1.3345
C2	1.3345

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

using model chemistry: MP2/CEP-121G*

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)