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	hartrees
Energy at 0K	-153.232432
Energy at 298.15K	-153.231602
HF Energy	-152.550232
Nuclear repulsion energy	77.083957

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3466	3298	0.00
2	Σ_g	2207	2100	0.00
3	Σ_g	908	863	0.00
4	Σ_u	3465	3297	169.33
5	Σ_u	2016	1918	1.01
6	Π_g	604	575	0.00
6	Π_g	604	575	0.00
7	Π_g	525	499	0.00
7	Π_g	525	499	0.00
8	Π_u	630	599	76.22
8	Π_u	630	599	76.22
9	Π_u	240	228	8.11
9	Π_u	240	228	8.11

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.681
C2	0.000	0.000	-0.681
C3	0.000	0.000	1.896
C4	0.000	0.000	-1.896
H5	0.000	0.000	2.955
H6	0.000	0.000	-2.955

	C1	C2	C3	C4	H5	H6
C1		1.3613	1.2154	2.5767	2.2746	3.6359
C2	1.3613		2.5767	1.2154	3.6359	2.2746
C3	1.2154	2.5767		3.7922	1.0592	4.8513
C4	2.5767	1.2154	3.7922		4.8513	1.0592
H5	2.2746	3.6359	1.0592	4.8513		5.9105
H6	3.6359	2.2746	4.8513	1.0592	5.9105

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/aug-cc-pVTZ

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/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)