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	hartrees
Energy at 0K	-153.067868
Energy at 298.15K	-153.066493
HF Energy	-152.532290
Nuclear repulsion energy	76.758575

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3499	3342	0.00
2	Σ_g	2308	2204	0.00
3	Σ_g	894	854	0.00
4	Σ_u	3499	3342	145.64
5	Σ_u	2106	2012	0.01
6	Π_g	660	630	0.00
6	Π_g	660	630	0.00
7	Π_g	243	232	0.00
7	Π_g	243	232	0.00
8	Π_u	663	633	75.07
8	Π_u	663	633	75.07
9	Π_u	220	210	5.69
9	Π_u	220	210	5.69

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	1.904
C4	0.000	0.000	-1.904
H5	0.000	0.000	2.969
H6	0.000	0.000	-2.969

	C1	C2	C3	C4	H5	H6
C1		1.3873	1.2103	2.5976	2.2757	3.6631
C2	1.3873		2.5976	1.2103	3.6631	2.2757
C3	1.2103	2.5976		3.8079	1.0654	4.8734
C4	2.5976	1.2103	3.8079		4.8734	1.0654
H5	2.2757	3.6631	1.0654	4.8734		5.9388
H6	3.6631	2.2757	4.8734	1.0654	5.9388

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/6-311G**

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/6-311G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)