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	hartrees
Energy at 0K	-152.521694
Energy at 298.15K	-152.521122
HF Energy	-152.521694
Nuclear repulsion energy	76.752768

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3432	3362	0.00
2	Σ_g	2280	2234	0.00
3	Σ_g	935	916	0.00
4	Σ_u	3433	3363	196.98
5	Σ_u	2071	2029	0.43
6	Π_g	753	737	0.00
6	Π_g	753	737	0.00
7	Π_g	599	587	0.00
7	Π_g	599	587	0.00
8	Π_u	627	614	133.47
8	Π_u	627	614	133.47
9	Π_u	254	249	9.34
9	Π_u	254	249	9.34

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.678
C2	0.000	0.000	-0.678
C3	0.000	0.000	1.902
C4	0.000	0.000	-1.902
H5	0.000	0.000	2.977
H6	0.000	0.000	-2.977

	C1	C2	C3	C4	H5	H6
C1		1.3554	1.2243	2.5797	2.2990	3.6543
C2	1.3554		2.5797	1.2243	3.6543	2.2990
C3	1.2243	2.5797		3.8040	1.0747	4.8786
C4	2.5797	1.2243	3.8040		4.8786	1.0747
H5	2.2990	3.6543	1.0747	4.8786		5.9533
H6	3.6543	2.2990	4.8786	1.0747	5.9533

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: LSDA/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	0.305
2	C	0.305
3	C	-0.619
4	C	-0.619
5	H	0.314
6	H	0.314

<r²>	78.912
(<r²>)^1/2	8.883

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: LSDA/6-31G

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)