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	hartrees
Energy at 0K	-153.196413
Energy at 298.15K	-153.195491
HF Energy	-152.549369
Nuclear repulsion energy	76.754927

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	Σ_g	3458	3371
2	Σ_g	2234	2178
3	Σ_g	887	865
4	Σ_u	3454	3367
5	Σ_u	2051	1999
6	Π_g	623	608
6	Π_g	623	608
7	Π_g	474	462
7	Π_g	474	462
8	Π_u	634	618
8	Π_u	634	618
9	Π_u	227	222
9	Π_u	227	222

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.689
C2	0.000	0.000	-0.689
C3	0.000	0.000	1.904
C4	0.000	0.000	-1.904
H5	0.000	0.000	2.968
H6	0.000	0.000	-2.968

	C1	C2	C3	C4	H5	H6
C1		1.3787	1.2150	2.5937	2.2789	3.6575
C2	1.3787		2.5937	1.2150	3.6575	2.2789
C3	1.2150	2.5937		3.8086	1.0639	4.8725
C4	2.5937	1.2150	3.8086		4.8725	1.0639
H5	2.2789	3.6575	1.0639	4.8725		5.9364
H6	3.6575	2.2789	4.8725	1.0639	5.9364

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)/cc-pVTZ

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)/cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)