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	hartrees
Energy at 0K	-153.340404
Energy at 298.15K	-153.339819
HF Energy	-153.159344
Nuclear repulsion energy	76.768278

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3502	3331	0.00
2	Σ_g	2249	2139	0.00
3	Σ_g	915	871	0.00
4	Σ_u	3503	3332	183.11
5	Σ_u	2073	1971	2.59
6	Π_g	687	654	0.00
6	Π_g	687	654	0.00
7	Π_g	617	587	0.00
7	Π_g	617	587	0.00
8	Π_u	627	596	123.66
8	Π_u	627	596	123.66
9	Π_u	263	250	9.47
9	Π_u	263	250	9.47

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.688
C2	0.000	0.000	-0.688
C3	0.000	0.000	1.905
C4	0.000	0.000	-1.905
H5	0.000	0.000	2.970
H6	0.000	0.000	-2.970

	C1	C2	C3	C4	H5	H6
C1		1.3768	1.2169	2.5937	2.2815	3.6583
C2	1.3768		2.5937	1.2169	3.6583	2.2815
C3	1.2169	2.5937		3.8106	1.0646	4.8752
C4	2.5937	1.2169	3.8106		4.8752	1.0646
H5	2.2815	3.6583	1.0646	4.8752		5.9398
H6	3.6583	2.2815	4.8752	1.0646	5.9398

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: B2PLYP=FULL/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: B2PLYP=FULL/6-31+G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)