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	hartrees
Energy at 0K	-153.545389
Energy at 298.15K	-153.544672
HF Energy	-153.545389
Nuclear repulsion energy	77.437728

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3468	3353	0.00
2	Σ_g	2281	2205	0.00
3	Σ_g	915	884	0.00
4	Σ_u	3469	3354	185.00
5	Σ_u	2113	2043	2.83
6	Π_g	663	641	0.00
6	Π_g	663	641	0.00
7	Π_g	533	515	0.00
7	Π_g	533	515	0.00
8	Π_u	667	645	90.22
8	Π_u	667	645	90.22
9	Π_u	239	231	7.57
9	Π_u	239	231	7.57

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	1.886
C4	0.000	0.000	-1.886
H5	0.000	0.000	2.947
H6	0.000	0.000	-2.947

	C1	C2	C3	C4	H5	H6
C1		1.3638	1.2042	2.5679	2.2654	3.6291
C2	1.3638		2.5679	1.2042	3.6291	2.2654
C3	1.2042	2.5679		3.7721	1.0612	4.8333
C4	2.5679	1.2042	3.7721		4.8333	1.0612
H5	2.2654	3.6291	1.0612	4.8333		5.8945
H6	3.6291	2.2654	4.8333	1.0612	5.8945

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: B3LYPultrafine/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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Number	Element	Mulliken
1	C	0.485
2	C	0.485
3	C	-0.615
4	C	-0.615
5	H	0.130
6	H	0.130

<r²>	78.407
(<r²>)^1/2	8.855

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B3LYPultrafine/cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)