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	hartrees
Energy at 0K	-153.037808
Energy at 298.15K
HF Energy	-152.509498
Nuclear repulsion energy	75.993925

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3471	3348	0.00
2	Σ_g	2289	2208	0.00
3	Σ_g	892	860	0.00
4	Σ_u	3471	3348	147.63
5	Σ_u	2090	2016	1.26
6	Π_g	583	563	0.00
6	Π_g	583	563	0.00
7	Π_g	631i	608i	0.00
7	Π_g	631i	608i	0.00
8	Π_u	563	543	83.94
8	Π_u	563	543	83.94
9	Π_u	156	151	3.50
9	Π_u	156	151	3.50

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.699
C2	0.000	0.000	-0.699
C3	0.000	0.000	1.923
C4	0.000	0.000	-1.923
H5	0.000	0.000	2.999
H6	0.000	0.000	-2.999

	C1	C2	C3	C4	H5	H6
C1		1.3974	1.2245	2.6219	2.3000	3.6973
C2	1.3974		2.6219	1.2245	3.6973	2.3000
C3	1.2245	2.6219		3.8464	1.0755	4.9219
C4	2.6219	1.2245	3.8464		4.9219	1.0755
H5	2.3000	3.6973	1.0755	4.9219		5.9973
H6	3.6973	2.3000	4.9219	1.0755	5.9973

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: CCD/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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All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: CCD/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)