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	hartrees
Energy at 0K	-153.495782
Energy at 298.15K	-153.495332
HF Energy	-153.495782
Nuclear repulsion energy	76.930076

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3480	3351	0.00
2	Σ_g	2286	2201	0.00
3	Σ_g	921	887	0.00
4	Σ_u	3482	3352	199.50
5	Σ_u	2111	2033	5.30
6	Π_g	774	745	0.00
6	Π_g	774	745	0.00
7	Π_g	625	602	0.00
7	Π_g	625	602	0.00
8	Π_u	654	630	124.75
8	Π_u	654	630	124.75
9	Π_u	272	262	11.39
9	Π_u	272	262	11.39

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.685
C2	0.000	0.000	-0.685
C3	0.000	0.000	1.899
C4	0.000	0.000	-1.899
H5	0.000	0.000	2.965
H6	0.000	0.000	-2.965

	C1	C2	C3	C4	H5	H6
C1		1.3691	1.2143	2.5834	2.2806	3.6497
C2	1.3691		2.5834	1.2143	3.6497	2.2806
C3	1.2143	2.5834		3.7977	1.0663	4.8640
C4	2.5834	1.2143	3.7977		4.8640	1.0663
H5	2.2806	3.6497	1.0663	4.8640		5.9303
H6	3.6497	2.2806	4.8640	1.0663	5.9303

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: B3LYPultrafine/6-31+G**

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	0.627
2	C	0.627
3	C	-0.877
4	C	-0.877
5	H	0.250
6	H	0.250

<r²>	79.349
(<r²>)^1/2	8.908

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B3LYPultrafine/6-31+G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)