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	hartrees
Energy at 0K	-152.513912
Energy at 298.15K	-152.513209
HF Energy	-152.513912
Nuclear repulsion energy	77.338227

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3629	3305	0.00
2	Σ_g	2483	2261	0.00
3	Σ_g	938	854	0.00
4	Σ_u	3629	3304	188.76
5	Σ_u	2281	2077	2.34
6	Π_g	754	687	0.00
6	Π_g	754	687	0.00
7	Π_g	432	393	0.00
7	Π_g	432	393	0.00
8	Π_u	771	702	93.39
8	Π_u	771	702	93.39
9	Π_u	239	218	11.15
9	Π_u	239	218	11.15

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.696
C2	0.000	0.000	-0.696
C3	0.000	0.000	1.889
C4	0.000	0.000	-1.889
H5	0.000	0.000	2.951
H6	0.000	0.000	-2.951

	C1	C2	C3	C4	H5	H6
C1		1.3915	1.1934	2.5850	2.2550	3.6465
C2	1.3915		2.5850	1.1934	3.6465	2.2550
C3	1.1934	2.5850		3.7784	1.0616	4.8399
C4	2.5850	1.1934	3.7784		4.8399	1.0616
H5	2.2550	3.6465	1.0616	4.8399		5.9015
H6	3.6465	2.2550	4.8399	1.0616	5.9015

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: HF/aug-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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Number	Element	Mulliken
1	C	0.427
2	C	0.427
3	C	0.167
4	C	0.167
5	H	-0.594
6	H	-0.594

<r²>	78.928
(<r²>)^1/2	8.884

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HF/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)