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	hartrees
Energy at 0K	-152.535247
Energy at 298.15K	-152.534888
HF Energy	-152.535247
Nuclear repulsion energy	77.804809

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3626	3294	0.00
2	Σ_g	2485	2257	0.00
3	Σ_g	934	849	0.00
4	Σ_u	3625	3293	175.84
5	Σ_u	2285	2076	0.23
6	Π_g	822	747	0.00
6	Π_g	822	747	0.00
7	Π_g	579	526	0.00
7	Π_g	579	526	0.00
8	Π_u	825	749	87.07
8	Π_u	825	749	87.07
9	Π_u	256	232	10.94
9	Π_u	256	232	10.94

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.693
C2	0.000	0.000	-0.693
C3	0.000	0.000	1.878
C4	0.000	0.000	-1.878
H5	0.000	0.000	2.933
H6	0.000	0.000	-2.933

	C1	C2	C3	C4	H5	H6
C1		1.3867	1.1846	2.5713	2.2399	3.6265
C2	1.3867		2.5713	1.1846	3.6265	2.2399
C3	1.1846	2.5713		3.7559	1.0552	4.8111
C4	2.5713	1.1846	3.7559		4.8111	1.0552
H5	2.2399	3.6265	1.0552	4.8111		5.8664
H6	3.6265	2.2399	4.8111	1.0552	5.8664

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/6-311G**

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	-0.090
2	C	-0.090
3	C	-0.040
4	C	-0.040
5	H	0.130
6	H	0.130

<r²>	77.979
(<r²>)^1/2	8.831

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HF/6-311G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)