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	hartrees
Energy at 0K	-150.595772
Energy at 298.15K	-150.595418
HF Energy	-150.595772
Nuclear repulsion energy	77.726051

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3943	3220	0.00
2	Σ_g	2745	2241	0.00
3	Σ_g	969	791	0.00
4	Σ_u	3937	3215	398.76
5	Σ_u	2562	2092	46.77
6	Π_g	935	763	0.00
6	Π_g	935	763	0.00
7	Π_g	670	547	0.00
7	Π_g	670	547	0.00
8	Π_u	937	765	27.25
8	Π_u	937	765	27.25
9	Π_u	273	223	2.73
9	Π_u	273	223	2.73

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.704
C2	0.000	0.000	-0.704
C3	0.000	0.000	1.879
C4	0.000	0.000	-1.879
H5	0.000	0.000	2.945
H6	0.000	0.000	-2.945

	C1	C2	C3	C4	H5	H6
C1		1.4082	1.1746	2.5828	2.2405	3.6487
C2	1.4082		2.5828	1.1746	3.6487	2.2405
C3	1.1746	2.5828		3.7574	1.0659	4.8233
C4	2.5828	1.1746	3.7574		4.8233	1.0659
H5	2.2405	3.6487	1.0659	4.8233		5.8892
H6	3.6487	2.2405	4.8233	1.0659	5.8892

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/STO-3G

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	-0.030
2	C	-0.030
3	C	-0.088
4	C	-0.088
5	H	0.117
6	H	0.117

<r²>	77.330
(<r²>)^1/2	8.794

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HF/STO-3G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)