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	hartrees
Energy at 0K	-152.555237
Energy at 298.15K	-152.554889
HF Energy	-152.555237
Nuclear repulsion energy	77.937903

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3618	3294	0.00
2	Σ_g	2476	2254	0.00
3	Σ_g	931	848	0.00
4	Σ_u	3618	3294	179.33
5	Σ_u	2281	2077	2.40
6	Π_g	812	740	0.00
6	Π_g	812	740	0.00
7	Π_g	585	533	0.00
7	Π_g	585	533	0.00
8	Π_u	820	747	89.73
8	Π_u	820	747	89.73
9	Π_u	259	236	12.64
9	Π_u	259	236	12.64

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.692
C2	0.000	0.000	-0.692
C3	0.000	0.000	1.875
C4	0.000	0.000	-1.875
H5	0.000	0.000	2.929
H6	0.000	0.000	-2.929

	C1	C2	C3	C4	H5	H6
C1		1.3850	1.1822	2.5672	2.2360	3.6210
C2	1.3850		2.5672	1.1822	3.6210	2.2360
C3	1.1822	2.5672		3.7494	1.0538	4.8032
C4	2.5672	1.1822	3.7494		4.8032	1.0538
H5	2.2360	3.6210	1.0538	4.8032		5.8570
H6	3.6210	2.2360	4.8032	1.0538	5.8570

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: HF/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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Number	Element	Mulliken
1	C	0.726
2	C	0.726
3	C	-1.132
4	C	-1.132
5	H	0.406
6	H	0.406

<r²>	77.899
(<r²>)^1/2	8.826

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HF/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)