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	hartrees
Energy at 0K	-151.368853
Energy at 298.15K	-151.367738
HF Energy	-151.368853
Nuclear repulsion energy	76.002552

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3608	3296	0.00
2	Σ_g	2348	2145	0.00
3	Σ_g	921	842	0.00
4	Σ_u	3607	3296	386.97
5	Σ_u	2193	2003	42.99
6	Π_g	652	596	0.00
6	Π_g	652	596	0.00
7	Π_g	527	481	0.00
7	Π_g	527	481	0.00
8	Π_u	647	591	38.21
8	Π_u	647	591	38.21
9	Π_u	228	208	2.98
9	Π_u	228	208	2.98

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.695
C2	0.000	0.000	-0.695
C3	0.000	0.000	1.920
C4	0.000	0.000	-1.920
H5	0.000	0.000	3.008
H6	0.000	0.000	-3.008

	C1	C2	C3	C4	H5	H6
C1		1.3907	1.2251	2.6158	2.3123	3.7030
C2	1.3907		2.6158	1.2251	3.7030	2.3123
C3	1.2251	2.6158		3.8409	1.0872	4.9281
C4	2.6158	1.2251	3.8409		4.9281	1.0872
H5	2.3123	3.7030	1.0872	4.9281		6.0154
H6	3.7030	2.3123	4.9281	1.0872	6.0154

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: PBEPBE/STO-3G

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	-0.036
2	C	-0.036
3	C	-0.097
4	C	-0.097
5	H	0.133
6	H	0.133

<r²>	79.598
(<r²>)^1/2	8.922

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBEPBE/STO-3G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)