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	hartrees
Energy at 0K	-153.452048
Energy at 298.15K	-153.451358
HF Energy	-153.452048
Nuclear repulsion energy	77.257219

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3489	3489	0.00
2	Σ_g	2349	2349	0.00
3	Σ_g	917	917	0.00
4	Σ_u	3489	3489	160.62
5	Σ_u	2156	2156	0.28
6	Π_g	685	685	0.00
6	Π_g	685	685	0.00
7	Π_g	537	537	0.00
7	Π_g	537	537	0.00
8	Π_u	682	682	87.94
8	Π_u	682	682	87.94
9	Π_u	240	240	7.04
9	Π_u	240	240	7.04

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.688
C2	0.000	0.000	-0.688
C3	0.000	0.000	1.890
C4	0.000	0.000	-1.890
H5	0.000	0.000	2.955
H6	0.000	0.000	-2.955

	C1	C2	C3	C4	H5	H6
C1		1.3768	1.2020	2.5788	2.2665	3.6433
C2	1.3768		2.5788	1.2020	3.6433	2.2665
C3	1.2020	2.5788		3.7808	1.0645	4.8453
C4	2.5788	1.2020	3.7808		4.8453	1.0645
H5	2.2665	3.6433	1.0645	4.8453		5.9098
H6	3.6433	2.2665	4.8453	1.0645	5.9098

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: M06-2X/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	-0.131
2	C	-0.131
3	C	-0.169
4	C	-0.169
5	H	0.300
6	H	0.300

<r²>	78.604
(<r²>)^1/2	8.866

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: M06-2X/6-311G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)