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	hartrees
Energy at 0K	-153.317134
Energy at 298.15K	-153.316291
HF Energy	-153.146230
Nuclear repulsion energy	76.819077

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3513	3334	0.00
2	Σ_g	2263	2148	0.00
3	Σ_g	918	871	0.00
4	Σ_u	3514	3336	159.79
5	Σ_u	2088	1982	0.03
6	Π_g	628	597	0.00
7	Π_g	628	597	0.00
8	Π_g	560	532	0.00
9	Π_g	560	532	0.00
10	Π_u	546	518	97.01
11	Π_u	546	518	97.01
12	Π_u	259	246	3.17
13	Π_u	259	246	3.17

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	2.967
H6	0.000	0.000	-2.967

	C1	C2	C3	C4	H5	H6
C1		1.3708	1.2167	2.5875	2.2820	3.6528
C2	1.3708		2.5875	1.2167	3.6528	2.2820
C3	1.2167	2.5875		3.8043	1.0653	4.8696
C4	2.5875	1.2167	3.8043		4.8696	1.0653
H5	2.2820	3.6528	1.0653	4.8696		5.9348
H6	3.6528	2.2820	4.8696	1.0653	5.9348

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	0.545
2	C	0.545
3	C	-0.820
4	C	-0.820
5	H	0.275
6	H	0.275

<r²>	78.959
(<r²>)^1/2	8.886

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)