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	hartrees
Energy at 0K	-153.340683
Energy at 298.15K	-153.339994
HF Energy	-153.340683
Nuclear repulsion energy	77.420290

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3480	3344	0.00
2	Σ_g	2307	2217	0.00
3	Σ_g	923	887	0.00
4	Σ_u	3481	3345	189.96
5	Σ_u	2129	2046	2.21
6	Π_g	675	648	0.00
6	Π_g	675	648	0.00
7	Π_g	536	516	0.00
7	Π_g	536	516	0.00
8	Π_u	678	652	90.29
8	Π_u	678	652	90.29
9	Π_u	239	229	8.14
9	Π_u	239	229	8.14

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	1.886
C4	0.000	0.000	-1.886
H5	0.000	0.000	2.950
H6	0.000	0.000	-2.950

	C1	C2	C3	C4	H5	H6
C1		1.3640	1.2040	2.5680	2.2676	3.6316
C2	1.3640		2.5680	1.2040	3.6316	2.2676
C3	1.2040	2.5680		3.7721	1.0636	4.8356
C4	2.5680	1.2040	3.7721		4.8356	1.0636
H5	2.2676	3.6316	1.0636	4.8356		5.8992
H6	3.6316	2.2676	4.8356	1.0636	5.8992

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: PBE1PBE/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	0.456
2	C	0.456
3	C	-0.605
4	C	-0.605
5	H	0.149
6	H	0.149

<r²>	78.281
(<r²>)^1/2	8.848

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBE1PBE/cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)