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	hartrees
Energy at 0K	-152.517045
Energy at 298.15K	-152.516684
HF Energy	-152.517045
Nuclear repulsion energy	77.904322

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3649	3304	0.00
2	Σ_g	2502	2266	0.00
3	Σ_g	937	848	0.00
4	Σ_u	3648	3303	169.32
5	Σ_u	2306	2088	0.02
6	Π_g	807	730	0.00
6	Π_g	807	730	0.00
7	Π_g	594	538	0.00
7	Π_g	594	538	0.00
8	Π_u	800	724	83.14
8	Π_u	800	724	83.14
9	Π_u	261	237	7.86
9	Π_u	261	237	7.86

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	2.930
H6	0.000	0.000	-2.930

	C1	C2	C3	C4	H5	H6
C1		1.3846	1.1831	2.5677	2.2376	3.6223
C2	1.3846		2.5677	1.1831	3.6223	2.2376
C3	1.1831	2.5677		3.7508	1.0546	4.8054
C4	2.5677	1.1831	3.7508		4.8054	1.0546
H5	2.2376	3.6223	1.0546	4.8054		5.8599
H6	3.6223	2.2376	4.8054	1.0546	5.8599

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/6-31G(2df,p)

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	0.063
2	C	0.063
3	C	-0.318
4	C	-0.318
5	H	0.255
6	H	0.255

<r²>	77.486
(<r²>)^1/2	8.803

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HF/6-31G(2df,p)

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)