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	hartrees
Energy at 0K	-152.049971
Energy at 298.15K
HF Energy	-151.647586
Nuclear repulsion energy	76.128218

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	Σ_g	3422	3350
2	Σ_g	2196	2150
3	Σ_g	859	840
4	Σ_u	3422	3349
5	Σ_u	2003	1961
6	Π_g	560	548
6	Π_g	560	548
7	Π_g	721i	706i
7	Π_g	721i	706i
8	Π_u	500	489
8	Π_u	500	489
9	Π_u	97	95
9	Π_u	97	95

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.693
C2	0.000	0.000	-0.693
C3	0.000	0.000	1.921
C4	0.000	0.000	-1.921
H5	0.000	0.000	2.990
H6	0.000	0.000	-2.990

	C1	C2	C3	C4	H5	H6
C1		1.3863	1.2275	2.6138	2.2969	3.6832
C2	1.3863		2.6138	1.2275	3.6832	2.2969
C3	1.2275	2.6138		3.8413	1.0694	4.9107
C4	2.6138	1.2275	3.8413		4.9107	1.0694
H5	2.2969	3.6832	1.0694	4.9107		5.9801
H6	3.6832	2.2969	4.9107	1.0694	5.9801

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: MP4=FULL/3-21G

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: MP4=FULL/3-21G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)