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	hartrees
Energy at 0K	-153.026637
Energy at 298.15K	-153.025841
HF Energy	-152.506581
Nuclear repulsion energy	76.207295

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3516	3307	0.00
2	Σ_g	2328	2189	0.00
3	Σ_g	905	851	0.00
4	Σ_u	3517	3307	168.35
5	Σ_u	2142	2014	0.09
6	Π_g	652	613	0.00
6	Π_g	652	613	0.00
7	Π_g	511	481	0.00
7	Π_g	511	481	0.00
8	Π_u	652	613	79.61
8	Π_u	652	613	79.61
9	Π_u	234	220	5.57
9	Π_u	234	220	5.57

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.697
C2	0.000	0.000	-0.697
C3	0.000	0.000	1.917
C4	0.000	0.000	-1.917
H5	0.000	0.000	2.992
H6	0.000	0.000	-2.992

	C1	C2	C3	C4	H5	H6
C1		1.3944	1.2202	2.6146	2.2948	3.6892
C2	1.3944		2.6146	1.2202	3.6892	2.2948
C3	1.2202	2.6146		3.8348	1.0746	4.9094
C4	2.6146	1.2202	3.8348		4.9094	1.0746
H5	2.2948	3.6892	1.0746	4.9094		5.9839
H6	3.6892	2.2948	4.9094	1.0746	5.9839

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: MP3=FULL/cc-pVDZ

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: MP3=FULL/cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)