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	hartrees
Energy at 0K	-153.330391
Energy at 298.15K	-153.329736
HF Energy	-153.150332
Nuclear repulsion energy	76.848164

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3515	3515	0.00
2	Σ_g	2263	2263	0.00
3	Σ_g	918	918	0.00
4	Σ_u	3516	3516	171.88
5	Σ_u	2087	2087	0.06
6	Π_g	667	667	0.00
6	Π_g	667	667	0.00
7	Π_g	607	607	0.00
7	Π_g	607	607	0.00
8	Π_u	593	593	94.47
8	Π_u	593	593	94.47
9	Π_u	264	264	4.20
9	Π_u	264	264	4.20

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.685
C2	0.000	0.000	-0.685
C3	0.000	0.000	1.902
C4	0.000	0.000	-1.902
H5	0.000	0.000	2.965
H6	0.000	0.000	-2.965

	C1	C2	C3	C4	H5	H6
C1		1.3702	1.2166	2.5869	2.2799	3.6501
C2	1.3702		2.5869	1.2166	3.6501	2.2799
C3	1.2166	2.5869		3.8035	1.0633	4.8668
C4	2.5869	1.2166	3.8035		4.8668	1.0633
H5	2.2799	3.6501	1.0633	4.8668		5.9300
H6	3.6501	2.2799	4.8668	1.0633	5.9300

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/6-31G**

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/6-31G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)