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	hartrees
Energy at 0K	-153.268055
Energy at 298.15K	-153.267586
HF Energy	-153.268055
Nuclear repulsion energy	76.914318

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3528	3375	0.00
2	Σ_g	2333	2231	0.00
3	Σ_g	934	893	0.00
4	Σ_u	3529	3375	170.30
5	Σ_u	2124	2032	0.74
6	Π_g	773	739	0.00
6	Π_g	773	739	0.00
7	Π_g	623	596	0.00
7	Π_g	623	596	0.00
8	Π_u	704	674	132.97
8	Π_u	704	674	132.97
9	Π_u	248	238	8.70
9	Π_u	248	238	8.70

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.683
C2	0.000	0.000	-0.683
C3	0.000	0.000	1.900
C4	0.000	0.000	-1.900
H5	0.000	0.000	2.964
H6	0.000	0.000	-2.964

	C1	C2	C3	C4	H5	H6
C1		1.3660	1.2166	2.5826	2.2813	3.6473
C2	1.3660		2.5826	1.2166	3.6473	2.2813
C3	1.2166	2.5826		3.7992	1.0647	4.8639
C4	2.5826	1.2166	3.7992		4.8639	1.0647
H5	2.2813	3.6473	1.0647	4.8639		5.9286
H6	3.6473	2.2813	4.8639	1.0647	5.9286

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/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	0.200
2	C	0.200
3	C	-0.530
4	C	-0.530
5	H	0.330
6	H	0.330

<r²>	78.805
(<r²>)^1/2	8.877

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HSEh1PBE/6-31G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)