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	hartrees
Energy at 0K	-153.155194
Energy at 298.15K	-153.154444
HF Energy	-152.551733
Nuclear repulsion energy	77.081268

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3489	3258	0.00
2	Σ_g	2318	2164	0.00
3	Σ_g	897	837	0.00
4	Σ_u	3485	3254	155.44
5	Σ_u	2123	1982	0.23
6	Π_g	670	625	0.00
6	Π_g	670	625	0.00
7	Π_g	505	472	0.00
7	Π_g	505	472	0.00
8	Π_u	685	640	81.96
8	Π_u	685	640	81.96
9	Π_u	235	219	7.71
9	Π_u	235	219	7.71

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.691
C2	0.000	0.000	-0.691
C3	0.000	0.000	1.896
C4	0.000	0.000	-1.896
H5	0.000	0.000	2.958
H6	0.000	0.000	-2.958

	C1	C2	C3	C4	H5	H6
C1		1.3821	1.2048	2.5869	2.2667	3.6487
C2	1.3821		2.5869	1.2048	3.6487	2.2667
C3	1.2048	2.5869		3.7916	1.0619	4.8535
C4	2.5869	1.2048	3.7916		4.8535	1.0619
H5	2.2667	3.6487	1.0619	4.8535		5.9154
H6	3.6487	2.2667	4.8535	1.0619	5.9154

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

using model chemistry: CCD/cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)