1,3-Butadiene

This molecule has been computed with Kimball.exe and standard parameters. The wavy, delocalized, double bond node has been used. Since the molecule is flat no stereo projection is shown. The p-"orbitals" are fixed at the core locations. A partial double bond between the two central carbons produces a reduced bond lenth of 1.50 instead of 1.54 Å. The outer CC-bonds are 1.33 Å. The optimized Gaussian94 RHF/6-31g structure shows a much larger reduction of the middle bond to 1.465 Å, a difference which has been amply documented with other Kimball calculations.

 
Here are the data produced by Kimball and, for comparison, those by  Gaussian98  

1,3-Butadiene - Energies (measured in Hartree)       RHF/6-31g      RHF/6-31g opt
-----------------------------------------------

One electron energy               :  -408.53900     -413.509432      -413.645148
Two electron energy               :   150.10395      154.542935       154.575532
Nuclear repulsion Energy          :   104.11134      104.111312       104.205040
                                     ----------     -----------      -----------
Total Energy                 Etot :  -154.32371     -154.855185      -154.864576

Nucleus-Electron  pot.Energy Vne  :  -562.84931     -568.483767      -568.700643
Electron-Electron pot.Energy Vee  :   150.10395      154.542935       154.575532
Nucleus-Nucleus   pot.Energy Vnn  :   104.11134      104.111312       104.205040
                                     ----------     -----------      -----------
Total potential energy       V    :  -308.63402     -309.829520      -309.920071
Total kinetic   energy       T    :   154.31031      154.974335       155.055494
Virial ratio                -V/T  :     2.0000868      1.9992           1.9988

Electronic energy            Eel  :  -258.43505     -258.966497      -259.069617
C1C2                         Å    :     1.329          1.329            1.328
C2C2                         Å    :     1.504          1.504            1.465

1,3-Butadiene - Cartesian Coordinates (used by first Gaussian94 computation)

10

C  -1.274324  1.1846867  0.
C  -0.68094012  -4.4998611E-3  0.
C  0.8192346  -0.1088889  0.
C  1.4126185  -1.2980754  0.
H  -2.3544058  1.1846867  0.
H  -0.62486914  2.0476961  0.
H  -1.2713977  -0.90311225  0.
H  1.4096922  0.78972349  0.
H  2.4927003  -1.2980754  0.
H  0.76316362  -2.1610848  0.