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	hartrees
Energy at 0K	-153.253893
Energy at 298.15K	-153.253422
HF Energy	-153.253893
Nuclear repulsion energy	76.894783

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3529	3373	0.00
2	Σ_g	2336	2233	0.00
3	Σ_g	933	892	0.00
4	Σ_u	3529	3374	172.50
5	Σ_u	2127	2033	0.73
6	Π_g	772	738	0.00
6	Π_g	772	738	0.00
7	Π_g	622	595	0.00
7	Π_g	622	595	0.00
8	Π_u	707	676	133.36
8	Π_u	707	676	133.36
9	Π_u	247	236	8.73
9	Π_u	247	236	8.73

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.683
C2	0.000	0.000	-0.683
C3	0.000	0.000	1.900
C4	0.000	0.000	-1.900
H5	0.000	0.000	2.965
H6	0.000	0.000	-2.965

	C1	C2	C3	C4	H5	H6
C1		1.3670	1.2166	2.5836	2.2816	3.6485
C2	1.3670		2.5836	1.2166	3.6485	2.2816
C3	1.2166	2.5836		3.8002	1.0650	4.8651
C4	2.5836	1.2166	3.8002		4.8651	1.0650
H5	2.2816	3.6485	1.0650	4.8651		5.9301
H6	3.6485	2.2816	4.8651	1.0650	5.9301

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: PBE1PBE/6-31G

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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Number	Element	Mulliken
1	C	0.196
2	C	0.196
3	C	-0.528
4	C	-0.528
5	H	0.332
6	H	0.332

<r²>	78.844
(<r²>)^1/2	8.879

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBE1PBE/6-31G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)