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	hartrees
Energy at 0K	-153.413192
Energy at 298.15K	-153.407799
HF Energy	-153.497200
Nuclear repulsion energy	77.382232

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3505	3383	0.00
2	Σ_g	2309	2228	0.00
3	Σ_g	922	890	0.00
4	Σ_u	3507	3384	182.82
5	Σ_u	2127	2053	0.20
6	Π_g	627	605	0.00
6	Π_g	627	605	0.00
7	Π_g	541	522	0.00
7	Π_g	541	522	0.00
8	Π_u	603	582	77.99
8	Π_u	603	582	77.99
9	Π_u	241	233	5.00
9	Π_u	241	233	5.00

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	1.887
C4	0.000	0.000	-1.887
H5	0.000	0.000	2.949
H6	0.000	0.000	-2.949

	C1	C2	C3	C4	H5	H6
C1		1.3614	1.2067	2.5681	2.2686	3.6300
C2	1.3614		2.5681	1.2067	3.6300	2.2686
C3	1.2067	2.5681		3.7748	1.0619	4.8367
C4	2.5681	1.2067	3.7748		4.8367	1.0619
H5	2.2686	3.6300	1.0619	4.8367		5.8985
H6	3.6300	2.2686	4.8367	1.0619	5.8985

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: G4

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	0.215
2	C	0.215
3	C	-0.414
4	C	-0.414
5	H	0.198
6	H	0.198

<r²>	78.002
(<r²>)^1/2	8.832

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: G4

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)