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	hartrees
Energy at 0K	-153.412853
Energy at 298.15K	-153.412274
HF Energy	-153.412853
Nuclear repulsion energy	77.010244

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3500	3348	0.00
2	Σ_g	2310	2210	0.00
3	Σ_g	929	889	0.00
4	Σ_u	3502	3350	165.45
5	Σ_u	2130	2038	0.80
6	Π_g	718	687	0.00
6	Π_g	718	687	0.00
7	Π_g	616	590	0.00
7	Π_g	616	590	0.00
8	Π_u	610	583	102.06
8	Π_u	610	583	102.06
9	Π_u	268	256	5.76
9	Π_u	268	256	5.76

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	1.896
C4	0.000	0.000	-1.896
H5	0.000	0.000	2.964
H6	0.000	0.000	-2.964

	C1	C2	C3	C4	H5	H6
C1		1.3674	1.2128	2.5801	2.2801	3.6474
C2	1.3674		2.5801	1.2128	3.6474	2.2801
C3	1.2128	2.5801		3.7929	1.0673	4.8602
C4	2.5801	1.2128	3.7929		4.8602	1.0673
H5	2.2801	3.6474	1.0673	4.8602		5.9275
H6	3.6474	2.2801	4.8602	1.0673	5.9275

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: B3PW91/6-31G*

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	0.652
2	C	0.652
3	C	-0.921
4	C	-0.921
5	H	0.269
6	H	0.269

<r²>	78.495
(<r²>)^1/2	8.860

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B3PW91/6-31G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)