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	hartrees
Energy at 0K	-153.134842
Energy at 298.15K	-153.133804
HF Energy	-152.529152
Nuclear repulsion energy	76.607090

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3508	3327	0.00
2	Σ_g	2203	2090	0.00
3	Σ_g	899	853	0.00
4	Σ_u	3507	3327	165.26
5	Σ_u	2007	1904	0.02
6	Π_g	641	608	0.00
6	Π_g	641	608	0.00
7	Π_g	396	375	0.00
7	Π_g	396	375	0.00
8	Π_u	640	607	75.82
8	Π_u	640	607	75.82
9	Π_u	228	216	5.57
9	Π_u	228	216	5.57

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.686
C2	0.000	0.000	-0.686
C3	0.000	0.000	1.908
C4	0.000	0.000	-1.908
H5	0.000	0.000	2.972
H6	0.000	0.000	-2.972

	C1	C2	C3	C4	H5	H6
C1		1.3718	1.2223	2.5941	2.2865	3.6583
C2	1.3718		2.5941	1.2223	3.6583	2.2865
C3	1.2223	2.5941		3.8164	1.0642	4.8806
C4	2.5941	1.2223	3.8164		4.8806	1.0642
H5	2.2865	3.6583	1.0642	4.8806		5.9449
H6	3.6583	2.2865	4.8806	1.0642	5.9449

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=FULL/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: MP2=FULL/6-311G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)