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	hartrees
Energy at 0K	-153.389888
Energy at 298.15K	-153.384655
HF Energy	-153.481644
Nuclear repulsion energy	77.016696

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3494	3356	0.00
2	Σ_g	2302	2211	0.00
3	Σ_g	925	888	0.00
4	Σ_u	3497	3358	165.68
5	Σ_u	2128	2044	0.62
6	Π_g	720	691	0.00
6	Π_g	720	691	0.00
7	Π_g	609	585	0.00
7	Π_g	609	585	0.00
8	Π_u	589	566	95.67
8	Π_u	589	566	95.67
9	Π_u	272	261	4.83
9	Π_u	272	261	4.83

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	1.897
C4	0.000	0.000	-1.897
H5	0.000	0.000	2.963
H6	0.000	0.000	-2.963

	C1	C2	C3	C4	H5	H6
C1		1.3688	1.2122	2.5810	2.2786	3.6474
C2	1.3688		2.5810	1.2122	3.6474	2.2786
C3	1.2122	2.5810		3.7933	1.0664	4.8596
C4	2.5810	1.2122	3.7933		4.8596	1.0664
H5	2.2786	3.6474	1.0664	4.8596		5.9260
H6	3.6474	2.2786	4.8596	1.0664	5.9260

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: G3B3

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	-0.951
4	C	-0.951
5	H	0.230
6	H	0.230

<r²>	78.591
(<r²>)^1/2	8.865

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: G3B3

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)