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	hartrees
Energy at 0K	-153.282954
Energy at 298.15K	-153.282181
HF Energy	-153.282954
Nuclear repulsion energy	76.547416

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3423	3376	0.00
2	Σ_g	2232	2201	0.00
3	Σ_g	919	906	0.00
4	Σ_u	3425	3378	184.51
5	Σ_u	2056	2028	1.33
6	Π_g	666	657	0.00
6	Π_g	666	657	0.00
7	Π_g	571	563	0.00
7	Π_g	571	563	0.00
8	Π_u	544	537	95.41
8	Π_u	544	537	95.41
9	Π_u	260	257	4.27
9	Π_u	260	257	4.27

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	1.908
C4	0.000	0.000	-1.908
H5	0.000	0.000	2.981
H6	0.000	0.000	-2.981

	C1	C2	C3	C4	H5	H6
C1		1.3649	1.2256	2.5905	2.2986	3.6634
C2	1.3649		2.5905	1.2256	3.6634	2.2986
C3	1.2256	2.5905		3.8161	1.0730	4.8890
C4	2.5905	1.2256	3.8161		4.8890	1.0730
H5	2.2986	3.6634	1.0730	4.8890		5.9620
H6	3.6634	2.2986	4.8890	1.0730	5.9620

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: PBEPBEultrafine/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	0.623
2	C	0.623
3	C	-0.823
4	C	-0.823
5	H	0.201
6	H	0.201

<r²>	79.272
(<r²>)^1/2	8.904

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBEPBEultrafine/6-31G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)