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	hartrees
Energy at 0K	-153.546821
Energy at 298.15K	-153.546089
HF Energy	-153.546821
Nuclear repulsion energy	77.435719

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3466	3353	0.00
2	Σ_g	2279	2205	0.00
3	Σ_g	916	886	0.00
4	Σ_u	3468	3355	187.62
5	Σ_u	2111	2043	5.51
6	Π_g	660	639	0.00
6	Π_g	660	639	0.00
7	Π_g	528	511	0.00
7	Π_g	528	511	0.00
8	Π_u	666	644	83.10
8	Π_u	666	644	83.10
9	Π_u	237	229	9.05
9	Π_u	237	229	9.05

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.682
C2	0.000	0.000	-0.682
C3	0.000	0.000	1.886
C4	0.000	0.000	-1.886
H5	0.000	0.000	2.947
H6	0.000	0.000	-2.947

	C1	C2	C3	C4	H5	H6
C1		1.3637	1.2042	2.5679	2.2656	3.6293
C2	1.3637		2.5679	1.2042	3.6293	2.2656
C3	1.2042	2.5679		3.7721	1.0614	4.8335
C4	2.5679	1.2042	3.7721		4.8335	1.0614
H5	2.2656	3.6293	1.0614	4.8335		5.8949
H6	3.6293	2.2656	4.8335	1.0614	5.8949

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: B3LYP/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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Calc. vs exp. Bad Vib. HF vs MP2 Bad scale factors Low excited states Oddities NaCN Is not linear FAQ Help Units Choose Units Energy Bond length Rotational Constant Moment of Inertia Dipole and Quadrupole Polarizability Explanations Hartree cm-1 Debye Credits Just show me Show me a calculated geometry Summary Using older interface Limit Basis sets Method options List Recent molecules Choose a few Molecules Number of atoms By heavy atoms Diatomics InChI Deuterated Dimers Geometry Point group Point group count Bonds types Isodesmic reactions Bad point group Multiple conformers, states Vibrations Big anharmonicity Energy Enthalpy at 0 Kelvin Similar molecules Similar Isomers Cis/trans Tautomers Multiple conformers, states Ions, Dipoles, etc. List Ions Ionization changes point group Dipole Quadrupole Polarizability Proton Affinities Index of CCCBDB Feedback Error form Wants
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Number	Element	Mulliken
1	C	0.722
2	C	0.722
3	C	-1.042
4	C	-1.042
5	H	0.320
6	H	0.320

<r²>	78.529
(<r²>)^1/2	8.862

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B3LYP/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)