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	hartrees
Energy at 0K	-153.356034
Energy at 298.15K	-153.355348
HF Energy	-153.356034
Nuclear repulsion energy	77.447761

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3481	3345	0.00
2	Σ_g	2303	2214	0.00
3	Σ_g	923	887	0.00
4	Σ_u	3482	3346	189.23
5	Σ_u	2127	2044	2.31
6	Π_g	674	648	0.00
6	Π_g	674	648	0.00
7	Π_g	538	517	0.00
7	Π_g	538	517	0.00
8	Π_u	678	652	90.34
8	Π_u	678	652	90.34
9	Π_u	239	230	8.14
9	Π_u	239	230	8.14

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	1.885
C4	0.000	0.000	-1.885
H5	0.000	0.000	2.948
H6	0.000	0.000	-2.948

	C1	C2	C3	C4	H5	H6
C1		1.3629	1.2039	2.5668	2.2670	3.6300
C2	1.3629		2.5668	1.2039	3.6300	2.2670
C3	1.2039	2.5668		3.7707	1.0631	4.8339
C4	2.5668	1.2039	3.7707		4.8339	1.0631
H5	2.2670	3.6300	1.0631	4.8339		5.8970
H6	3.6300	2.2670	4.8339	1.0631	5.8970

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: HSEh1PBE/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	0.477
2	C	0.477
3	C	-0.619
4	C	-0.619
5	H	0.142
6	H	0.142

<r²>	78.245
(<r²>)^1/2	8.846

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HSEh1PBE/cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)