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	hartrees
Energy at 0K	-152.448255
Energy at 298.15K	-152.448055
HF Energy	-152.448255
Nuclear repulsion energy	77.519842

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3673	3316	0.00
2	Σ_g	2503	2260	0.00
3	Σ_g	953	860	0.00
4	Σ_u	3671	3314	178.33
5	Σ_u	2271	2050	0.44
6	Π_g	962	869	0.00
6	Π_g	962	869	0.00
7	Π_g	632	571	0.00
7	Π_g	632	571	0.00
8	Π_u	912	824	154.50
8	Π_u	912	824	154.50
9	Π_u	252	227	11.58
9	Π_u	252	227	11.58

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.690
C2	0.000	0.000	-0.690
C3	0.000	0.000	1.886
C4	0.000	0.000	-1.886
H5	0.000	0.000	2.939
H6	0.000	0.000	-2.939

	C1	C2	C3	C4	H5	H6
C1		1.3799	1.1957	2.5757	2.2492	3.6291
C2	1.3799		2.5757	1.1957	3.6291	2.2492
C3	1.1957	2.5757		3.7714	1.0534	4.8249
C4	2.5757	1.1957	3.7714		4.8249	1.0534
H5	2.2492	3.6291	1.0534	4.8249		5.8783
H6	3.6291	2.2492	4.8249	1.0534	5.8783

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

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	-0.006
2	C	-0.006
3	C	-0.406
4	C	-0.406
5	H	0.412
6	H	0.412

<r²>	78.271
(<r²>)^1/2	8.847

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HF/6-31G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)