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	hartrees
Energy at 0K	-153.316658
Energy at 298.15K	-153.315489
HF Energy	-153.316658
Nuclear repulsion energy	76.832968

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3399	3364	0.00
2	Σ_g	2220	2197	0.00
3	Σ_g	912	902	0.00
4	Σ_u	3402	3367	147.95
5	Σ_u	2043	2021	1.97
6	Π_g	568	562	0.00
6	Π_g	568	562	0.00
7	Π_g	459	454	0.00
7	Π_g	459	454	0.00
8	Π_u	529	523	89.54
8	Π_u	529	523	89.54
9	Π_u	223	221	3.89
9	Π_u	223	221	3.89

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.681
C2	0.000	0.000	-0.681
C3	0.000	0.000	1.900
C4	0.000	0.000	-1.900
H5	0.000	0.000	2.972
H6	0.000	0.000	-2.972

	C1	C2	C3	C4	H5	H6
C1		1.3612	1.2198	2.5810	2.2914	3.6526
C2	1.3612		2.5810	1.2198	3.6526	2.2914
C3	1.2198	2.5810		3.8008	1.0716	4.8724
C4	2.5810	1.2198	3.8008		4.8724	1.0716
H5	2.2914	3.6526	1.0716	4.8724		5.9440
H6	3.6526	2.2914	4.8724	1.0716	5.9440

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/6-311G*

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	-0.092
2	C	-0.092
3	C	-0.169
4	C	-0.169
5	H	0.261
6	H	0.261

<r²>	79.147
(<r²>)^1/2	8.896

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBEPBEultrafine/6-311G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)