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	hartrees
Energy at 0K	-153.473203
Energy at 298.15K	-153.472024
HF Energy	-153.473203
Nuclear repulsion energy	76.855354

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3390	3382	0.00
2	Σ_g	2202	2197	0.00
3	Σ_g	903	900	0.00
4	Σ_u	3393	3385	140.43
5	Σ_u	2036	2031	2.15
6	Π_g	566	564	0.00
6	Π_g	566	564	0.00
7	Π_g	458	457	0.00
7	Π_g	458	457	0.00
8	Π_u	524	523	90.83
8	Π_u	524	523	90.83
9	Π_u	224	224	3.11
9	Π_u	224	224	3.11

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.682
C2	0.000	0.000	-0.682
C3	0.000	0.000	1.900
C4	0.000	0.000	-1.900
H5	0.000	0.000	2.970
H6	0.000	0.000	-2.970

	C1	C2	C3	C4	H5	H6
C1		1.3635	1.2185	2.5820	2.2879	3.6514
C2	1.3635		2.5820	1.2185	3.6514	2.2879
C3	1.2185	2.5820		3.8005	1.0694	4.8699
C4	2.5820	1.2185	3.8005		4.8699	1.0694
H5	2.2879	3.6514	1.0694	4.8699		5.9392
H6	3.6514	2.2879	4.8699	1.0694	5.9392

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: BLYP/6-311G*

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	-0.145
2	C	-0.145
3	C	-0.121
4	C	-0.121
5	H	0.266
6	H	0.266

<r²>	79.257
(<r²>)^1/2	8.903

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: BLYP/6-311G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)