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	hartrees
Energy at 0K	-153.070829
Energy at 298.15K
HF Energy	-152.506555
Nuclear repulsion energy	75.675761

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	Σ_g	3439	3310
2	Σ_g	2207	2124
3	Σ_g	882	849
4	Σ_u	3440	3311
5	Σ_u	2020	1945
6	Π_g	541	520
6	Π_g	540	520
7	Π_g	662i	637i
7	Π_g	662i	637i
8	Π_u	500	481
8	Π_u	500	481
9	Π_u	114	110
9	Π_u	114	110

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.697
C2	0.000	0.000	-0.697
C3	0.000	0.000	1.932
C4	0.000	0.000	-1.932
H5	0.000	0.000	3.009
H6	0.000	0.000	-3.009

	C1	C2	C3	C4	H5	H6
C1		1.3944	1.2345	2.6289	2.3122	3.7066
C2	1.3944		2.6289	1.2345	3.7066	2.3122
C3	1.2345	2.6289		3.8634	1.0777	4.9411
C4	2.6289	1.2345	3.8634		4.9411	1.0777
H5	2.3122	3.7066	1.0777	4.9411		6.0188
H6	3.7066	2.3122	4.9411	1.0777	6.0188

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	180.000		C1	C3	H5	180.000
C2	C1	C3	180.000		C2	C4	H6	180.000

All results from a given calculation for C₄H₂ (Diacetylene)

using model chemistry: CCSD(T)/aug-cc-pVDZ

States and conformations

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: CCSD(T)/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)