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	hartrees
Energy at 0K	-153.478881
Energy at 298.15K	-153.477936
HF Energy	-153.478881
Nuclear repulsion energy	76.866912

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3405	3391	0.00
2	Σ_g	2200	2192	0.00
3	Σ_g	902	899	0.00
4	Σ_u	3407	3394	171.81
5	Σ_u	2036	2028	2.38
6	Π_g	605	602	0.00
6	Π_g	605	602	0.00
7	Π_g	498	496	0.00
7	Π_g	498	496	0.00
8	Π_u	597	595	83.23
8	Π_u	597	595	83.23
9	Π_u	228	228	5.17
9	Π_u	228	228	5.17

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	2.968
H6	0.000	0.000	-2.968

	C1	C2	C3	C4	H5	H6
C1		1.3640	1.2183	2.5823	2.2859	3.6499
C2	1.3640		2.5823	1.2183	3.6499	2.2859
C3	1.2183	2.5823		3.8006	1.0676	4.8682
C4	2.5823	1.2183	3.8006		4.8682	1.0676
H5	2.2859	3.6499	1.0676	4.8682		5.9358
H6	3.6499	2.2859	4.8682	1.0676	5.9358

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	-0.142
2	C	-0.142
3	C	0.013
4	C	0.013
5	H	0.129
6	H	0.129

<r²>	79.271
(<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)