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	hartrees
Energy at 0K	-153.026583
Energy at 298.15K	-153.025756
HF Energy	-152.506642
Nuclear repulsion energy	76.611950

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3525	3322	0.00
2	Σ_g	2318	2185	0.00
3	Σ_g	903	851	0.00
4	Σ_u	3525	3321	144.03
5	Σ_u	2124	2001	1.00
6	Π_g	619	583	0.00
6	Π_g	619	583	0.00
7	Π_g	530	500	0.00
7	Π_g	530	500	0.00
8	Π_u	615	580	119.91
8	Π_u	615	580	119.91
9	Π_u	245	231	6.82
9	Π_u	245	231	6.82

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.694
C2	0.000	0.000	-0.694
C3	0.000	0.000	1.908
C4	0.000	0.000	-1.908
H5	0.000	0.000	2.973
H6	0.000	0.000	-2.973

	C1	C2	C3	C4	H5	H6
C1		1.3881	1.2142	2.6023	2.2784	3.6666
C2	1.3881		2.6023	1.2142	3.6666	2.2784
C3	1.2142	2.6023		3.8165	1.0643	4.8808
C4	2.6023	1.2142	3.8165		4.8808	1.0643
H5	2.2784	3.6666	1.0643	4.8808		5.9450
H6	3.6666	2.2784	4.8808	1.0643	5.9450

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/6-31+G**

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/6-31+G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)