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	hartrees
Energy at 0K	-153.500736
Energy at 298.15K
HF Energy	-153.500736
Nuclear repulsion energy	76.760413

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3479	3376	0.00
2	Σ_g	2285	2217	0.00
3	Σ_g	919	892	0.00
4	Σ_u	3480	3377	197.56
5	Σ_u	2105	2043	5.53
6	Π_g	608	590	0.00
6	Π_g	608	590	0.00
7	Π_g	63i	61i	0.00
7	Π_g	63i	61i	0.00
8	Π_u	601	583	89.32
8	Π_u	601	583	89.32
9	Π_u	208	202	6.62
9	Π_u	208	202	6.62

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.686
C2	0.000	0.000	-0.686
C3	0.000	0.000	1.903
C4	0.000	0.000	-1.903
H5	0.000	0.000	2.972
H6	0.000	0.000	-2.972

	C1	C2	C3	C4	H5	H6
C1		1.3714	1.2172	2.5886	2.2867	3.6581
C2	1.3714		2.5886	1.2172	3.6581	2.2867
C3	1.2172	2.5886		3.8057	1.0695	4.8753
C4	2.5886	1.2172	3.8057		4.8753	1.0695
H5	2.2867	3.6581	1.0695	4.8753		5.9448
H6	3.6581	2.2867	4.8753	1.0695	5.9448

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: B3LYPultrafine/aug-cc-pVDZ

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	0.229
2	C	0.229
3	C	0.680
4	C	0.680
5	H	-0.909
6	H	-0.909

<r²>	79.679
(<r²>)^1/2	8.926

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B3LYPultrafine/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)