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	hartrees
Energy at 0K	-153.283964
Energy at 298.15K	-153.283397
HF Energy	-153.283964
Nuclear repulsion energy	77.052780

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3514	3339	0.00
2	Σ_g	2329	2213	0.00
3	Σ_g	933	887	0.00
4	Σ_u	3515	3341	172.02
5	Σ_u	2146	2039	0.53
6	Π_g	712	677	0.00
6	Π_g	712	677	0.00
7	Π_g	623	592	0.00
7	Π_g	623	592	0.00
8	Π_u	622	591	101.28
8	Π_u	622	591	101.28
9	Π_u	266	253	5.83
9	Π_u	266	253	5.83

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.684
C2	0.000	0.000	-0.684
C3	0.000	0.000	1.895
C4	0.000	0.000	-1.895
H5	0.000	0.000	2.963
H6	0.000	0.000	-2.963

	C1	C2	C3	C4	H5	H6
C1		1.3681	1.2112	2.5793	2.2785	3.6467
C2	1.3681		2.5793	1.2112	3.6467	2.2785
C3	1.2112	2.5793		3.7905	1.0673	4.8579
C4	2.5793	1.2112	3.7905		4.8579	1.0673
H5	2.2785	3.6467	1.0673	4.8579		5.9252
H6	3.6467	2.2785	4.8579	1.0673	5.9252

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: PBE1PBE/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: PBE1PBE/6-31G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)