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	hartrees
Energy at 0K	-153.007514
Energy at 298.15K	-153.006459
HF Energy	-152.496000
Nuclear repulsion energy	76.460104

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3537	3312	0.00
2	Σ_g	2224	2082	0.00
3	Σ_g	908	850	0.00
4	Σ_u	3537	3312	160.40
5	Σ_u	2033	1904	0.18
6	Π_g	606	568	0.00
6	Π_g	606	568	0.00
7	Π_g	460	431	0.00
7	Π_g	460	431	0.00
8	Π_u	534	500	95.05
8	Π_u	534	500	95.05
9	Π_u	247	231	1.91
9	Π_u	247	231	1.91

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.687
C2	0.000	0.000	-0.687
C3	0.000	0.000	1.913
C4	0.000	0.000	-1.913
H5	0.000	0.000	2.976
H6	0.000	0.000	-2.976

	C1	C2	C3	C4	H5	H6
C1		1.3749	1.2251	2.6000	2.2882	3.6631
C2	1.3749		2.6000	1.2251	3.6631	2.2882
C3	1.2251	2.6000		3.8251	1.0631	4.8882
C4	2.6000	1.2251	3.8251		4.8882	1.0631
H5	2.2882	3.6631	1.0631	4.8882		5.9513
H6	3.6631	2.2882	4.8882	1.0631	5.9513

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: MP2/6-31G**

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: MP2/6-31G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)