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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	-75.730911
Energy at 298.15K	-75.727885
HF Energy	-75.383970
Nuclear repulsion energy	15.191596

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.627
C2	0.000	0.000	-0.627

	C1	C2
C1		1.2540
C2	1.2540

	hartrees
Energy at 0K	-75.739606
Energy at 298.15K	-75.736578
HF Energy	-75.479016
Nuclear repulsion energy	14.461141

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

using model chemistry: QCISD/6-31G(2df,p)

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		1.3174
C2	1.3174

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

using model chemistry: QCISD/6-31G(2df,p)

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)