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	hartrees
Energy at 0K	-153.063972
Energy at 298.15K	-153.062889
HF Energy	-152.501507
Nuclear repulsion energy	75.634156

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	Σ_g	3465	3344
2	Σ_g	2173	2097
3	Σ_g	885	854
4	Σ_u	3465	3344
5	Σ_u	1991	1922
6	Π_g	593	572
6	Π_g	593	572
7	Π_g	457	441
7	Π_g	457	441
8	Π_u	572	552
8	Π_u	572	552
9	Π_u	221	214
9	Π_u	221	214

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.695
C2	0.000	0.000	-0.695
C3	0.000	0.000	1.933
C4	0.000	0.000	-1.933
H5	0.000	0.000	3.011
H6	0.000	0.000	-3.011

	C1	C2	C3	C4	H5	H6
C1		1.3903	1.2375	2.6278	2.3158	3.7061
C2	1.3903		2.6278	1.2375	3.7061	2.3158
C3	1.2375	2.6278		3.8653	1.0783	4.9435
C4	2.6278	1.2375	3.8653		4.9435	1.0783
H5	2.3158	3.7061	1.0783	4.9435		6.0218
H6	3.7061	2.3158	4.9435	1.0783	6.0218

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: MP4=FULL/cc-pVDZ

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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All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: MP4=FULL/cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)