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	hartrees
Energy at 0K	-153.340004
Energy at 298.15K	-153.339092
HF Energy	-153.340004
Nuclear repulsion energy	76.938355

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3394	3356	0.00
2	Σ_g	2209	2184	0.00
3	Σ_g	909	899	0.00
4	Σ_u	3397	3359	184.96
5	Σ_u	2042	2019	6.62
6	Π_g	607	600	0.00
6	Π_g	607	600	0.00
7	Π_g	504	499	0.00
7	Π_g	504	499	0.00
8	Π_u	607	601	82.03
8	Π_u	607	601	82.03
9	Π_u	229	226	8.18
9	Π_u	229	226	8.18

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.680
C2	0.000	0.000	-0.680
C3	0.000	0.000	1.898
C4	0.000	0.000	-1.898
H5	0.000	0.000	2.968
H6	0.000	0.000	-2.968

	C1	C2	C3	C4	H5	H6
C1		1.3608	1.2174	2.5783	2.2873	3.6482
C2	1.3608		2.5783	1.2174	3.6482	2.2873
C3	1.2174	2.5783		3.7957	1.0699	4.8656
C4	2.5783	1.2174	3.7957		4.8656	1.0699
H5	2.2873	3.6482	1.0699	4.8656		5.9355
H6	3.6482	2.2873	4.8656	1.0699	5.9355

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: PBEPBEultrafine/aug-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	0.758
2	C	0.758
3	C	-1.071
4	C	-1.071
5	H	0.314
6	H	0.314

<r²>	79.252
(<r²>)^1/2	8.902

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBEPBEultrafine/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)