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	hartrees
Energy at 0K	-153.548285
Energy at 298.15K	-153.547508
HF Energy	-153.548285
Nuclear repulsion energy	77.323219

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3464	3344	0.00
2	Σ_g	2265	2186	0.00
3	Σ_g	917	885	0.00
4	Σ_u	3466	3346	180.11
5	Σ_u	2095	2022	5.67
6	Π_g	648	626	0.00
6	Π_g	648	626	0.00
7	Π_g	517	499	0.00
7	Π_g	517	499	0.00
8	Π_u	651	628	83.68
8	Π_u	651	628	83.68
9	Π_u	236	228	8.64
9	Π_u	236	228	8.64

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	1.889
C4	0.000	0.000	-1.889
H5	0.000	0.000	2.952
H6	0.000	0.000	-2.952

	C1	C2	C3	C4	H5	H6
C1		1.3619	1.2078	2.5697	2.2708	3.6327
C2	1.3619		2.5697	1.2078	3.6327	2.2708
C3	1.2078	2.5697		3.7775	1.0630	4.8405
C4	2.5697	1.2078	3.7775		4.8405	1.0630
H5	2.2708	3.6327	1.0630	4.8405		5.9035
H6	3.6327	2.2708	4.8405	1.0630	5.9035

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: TPSSh/aug-cc-pVTZ

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	0.855
2	C	0.855
3	C	-0.854
4	C	-0.854
5	H	-0.001
6	H	-0.001

<r²>	78.525
(<r²>)^1/2	8.861

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: TPSSh/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)