return to home page

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   245  
Energy 298.15K   234  
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   207  
HOMO-LUMO Energies HOMO energies   200  
Barriers to Internal Rotation internal rotation  0 
Geometries Cartesians x188  
Internal Coordinates bond lengths bond angles x188x
Products of moments of inertia moments of inertia x205x
Rotational Constants rotational constants x210x
Point Group  210 
Vibrations Vibrational Frequencies vibrations x209x
Vibrational Intensities  206 
Zero-point energies x209x
Vibrational scaling factors x
Anharmonic frequencies and constants      
Electronic States Electronic states x 0  
Electrostatics Atom charges   198  
Dipole dipole x172x
Quadrupole quadrupole  196 
Polarizability polarizability  173 
Other results Spin   11  
Number of basis functions   32  
Diagnostics   5  
Conformations   1