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	hartrees
Energy at 0K	-153.426875
Energy at 298.15K	-153.426123
HF Energy	-153.206616
Nuclear repulsion energy	77.297436

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3484	3330	0.00
2	Σ_g	2244	2145	0.00
3	Σ_g	908	868	0.00
4	Σ_u	3479	3325	176.79
5	Σ_u	2071	1980	1.17
6	Π_g	654	625	0.00
6	Π_g	654	625	0.00
7	Π_g	518	495	0.00
7	Π_g	518	495	0.00
8	Π_u	665	635	86.50
8	Π_u	665	635	86.50
9	Π_u	239	228	7.60
9	Π_u	239	228	7.60

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.682
C2	0.000	0.000	-0.682
C3	0.000	0.000	1.890
C4	0.000	0.000	-1.890
H5	0.000	0.000	2.950
H6	0.000	0.000	-2.950

	C1	C2	C3	C4	H5	H6
C1		1.3633	1.2086	2.5719	2.2679	3.6312
C2	1.3633		2.5719	1.2086	3.6312	2.2679
C3	1.2086	2.5719		3.7805	1.0593	4.8398
C4	2.5719	1.2086	3.7805		4.8398	1.0593
H5	2.2679	3.6312	1.0593	4.8398		5.8991
H6	3.6312	2.2679	4.8398	1.0593	5.8991

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: B2PLYP=FULL/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: B2PLYP=FULL/cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)