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	hartrees
Energy at 0K	-153.237215
Energy at 298.15K	-153.235831
HF Energy	-153.109418
Nuclear repulsion energy	76.488041

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3508	3508	0.00
2	Σ_g	2261	2261	0.00
3	Σ_g	908	908	0.00
4	Σ_u	3508	3508	147.78
5	Σ_u	2058	2058	0.13
6	Π_g	615	615	0.00
6	Π_g	615	615	0.00
7	Π_g	284	284	0.00
7	Π_g	284	284	0.00
8	Π_u	609	609	127.79
8	Π_u	609	609	127.79
9	Π_u	221	221	4.15
9	Π_u	221	221	4.15

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.687
C2	0.000	0.000	-0.687
C3	0.000	0.000	1.911
C4	0.000	0.000	-1.911
H5	0.000	0.000	2.976
H6	0.000	0.000	-2.976

	C1	C2	C3	C4	H5	H6
C1		1.3743	1.2242	2.5985	2.2892	3.6635
C2	1.3743		2.5985	1.2242	3.6635	2.2892
C3	1.2242	2.5985		3.8228	1.0650	4.8877
C4	2.5985	1.2242	3.8228		4.8877	1.0650
H5	2.2892	3.6635	1.0650	4.8877		5.9527
H6	3.6635	2.2892	4.8877	1.0650	5.9527

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/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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Number	Element	Mulliken
1	C	0.156
2	C	0.156
3	C	-0.470
4	C	-0.470
5	H	0.313
6	H	0.313

<r²>	79.738
(<r²>)^1/2	8.930

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B2PLYP/6-31G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)