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	hartrees
Energy at 0K	-153.163148
Energy at 298.15K	-153.162323
HF Energy	-152.552889
Nuclear repulsion energy	77.059715

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3481	3331	0.00
2	Σ_g	2312	2213	0.00
3	Σ_g	898	859	0.00
4	Σ_u	3480	3331	155.15
5	Σ_u	2118	2027	1.03
6	Π_g	666	638	0.00
6	Π_g	666	638	0.00
7	Π_g	484	463	0.00
7	Π_g	484	463	0.00
8	Π_u	676	647	77.19
8	Π_u	676	647	77.19
9	Π_u	223	214	8.09
9	Π_u	223	214	8.09

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.691
C2	0.000	0.000	-0.691
C3	0.000	0.000	1.896
C4	0.000	0.000	-1.896
H5	0.000	0.000	2.959
H6	0.000	0.000	-2.959

	C1	C2	C3	C4	H5	H6
C1		1.3824	1.2051	2.5875	2.2674	3.6498
C2	1.3824		2.5875	1.2051	3.6498	2.2674
C3	1.2051	2.5875		3.7927	1.0623	4.8549
C4	2.5875	1.2051	3.7927		4.8549	1.0623
H5	2.2674	3.6498	1.0623	4.8549		5.9172
H6	3.6498	2.2674	4.8549	1.0623	5.9172

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: CCD/aug-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: CCD/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)