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	hartrees
Energy at 0K	-152.568501
Energy at 298.15K	-152.567860
HF Energy	-152.568501
Nuclear repulsion energy	77.289612

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3503	3351	0.00
2	Σ_g	2332	2231	0.00
3	Σ_g	919	880	0.00
4	Σ_u	3504	3352	163.06
5	Σ_u	2138	2046	0.06
6	Π_g	722	691	0.00
6	Π_g	722	691	0.00
7	Π_g	550	526	0.00
7	Π_g	550	526	0.00
8	Π_u	719	688	103.00
8	Π_u	719	688	103.00
9	Π_u	226	217	8.89
9	Π_u	226	217	8.89

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.681
C2	0.000	0.000	-0.681
C3	0.000	0.000	1.890
C4	0.000	0.000	-1.890
H5	0.000	0.000	2.952
H6	0.000	0.000	-2.952

	C1	C2	C3	C4	H5	H6
C1		1.3615	1.2092	2.5707	2.2708	3.6323
C2	1.3615		2.5707	1.2092	3.6323	2.2708
C3	1.2092	2.5707		3.7799	1.0616	4.8415
C4	2.5707	1.2092	3.7799		4.8415	1.0616
H5	2.2708	3.6323	1.0616	4.8415		5.9032
H6	3.6323	2.2708	4.8415	1.0616	5.9032

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: B1B95/3-21G

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	-0.023
2	C	-0.023
3	C	-0.278
4	C	-0.278
5	H	0.301
6	H	0.301

<r²>	78.308
(<r²>)^1/2	8.849

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B1B95/3-21G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)