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I.B.3. (II.A.2.)

All data (experiment and calculated) in the CCCBDB for C4H2 (Diacetylene)

Other names
Biethynyl; Biacetylene; 1,3-Butadiyne; Butadiyne; buta-1,3-diyne;
INChI
InChI=1/C4H2/c1-3-4-2/h1-2H

An "x" indicates that data is available. A number indicates how many calculations have been completed.
Property Experiment Calculated Comparison
Energies
Entropies
Enthalpy 298.15K enthalpy of formation x    
Enthalpy 0K enthalpy of formation      
Energy 0K   255  
Energy 298.15K   235  
Atomization Enthalpy 298.15K x222x
Atomization Enthalpy 0K  220 
Entropy (298.15K) entropy  198 
Entropy at any temperature   198  
Integrated Heat Capacity integrated heat capacity  198 
Heat Capacity (Cp) Heat capacity x198x
Nuclear Repulsion Energy   217  
HOMO-LUMO Energies HOMO energies   211  
Barriers to Internal Rotation internal rotation  0 
Geometries Cartesians x198  
Internal Coordinates bond lengths bond angles x198x
Products of moments of inertia moments of inertia x213x
Rotational Constants rotational constants x219x
Point Group  220 
Vibrations Vibrational Frequencies vibrations x218x
Vibrational Intensities  215 
Zero-point energies x218x
Vibrational scaling factors x
Anharmonic frequencies and constants      
Electronic States Electronic states x 0  
Electrostatics Atom charges   204  
Dipole dipole x177x
Quadrupole quadrupole  199 
Polarizability polarizability  179 
Other results Spin   9  
Number of basis functions   33  
Diagnostics   5  
Conformations   1