Lithium Hydride molecule (ab initio and Kimball)

The total density of the groundstate of the LiH molecule has been computed with GAMESS (Gaussian98 gives the same result, but a contour drawing program has to be bought separately). The structure and energy are optimized at the RHF/6-311G model chemistry. The density contours were plotted with (slightly improved) Pltorb/Dendif, two accompanying free tools of (free) GAMESS (running under Linux (SuSE 5.2) and X-windows). The total energy -7.984655 in the vibrationless state compares with a Kimball value of -7.985005 hartree. The equatorial planes of the two Kimball spheres are superimposed on the density plot. The lowest contour is 0.01 electron per bohr3/2. 
LiH:
  Final Results of Parameter-Optimization
         RHF/6-311g   Kimball      D %
  Etot   -7.984655   -7.985005   -0.0044
  Re      1.605600    1.605630    0.0019
  Vne   -20.419674  -20.423953   -0.021
  Vee     3.468685    3.465214   -0.10
  
  Parameters determined: (-V/T = 2.0000000)
  k1 = 1.02897160  k2 = 1.23924503  
  s1 = 0.27885572  s2 = 0.29125954
  Kimball radii (bohr):
   P(Li 1s2)     Q(LiH)   R(exzentr.of H+)
   0.5630405   2.0221093   0.4490507

  Find Minimum of
  2.25*k1/P2 - 9/P + 2.25*k2/Q2 - 2/(P+Q) +
    1/(P+Q+R) - (3 - (R/Q)2)/Q + 3*s1/P +
    3*s2/Q
  gives the above Etot, and P,Q,R, from which
  Re, Vne, and Vee are computed.

  Parameter-Optimization with G2 Theory
          G2/6-311g   Kimball     D %
  Etot   -8.022475   -8.022485   -0.00012
  Re      1.5946      1.59415    -0.028
  Bond   56.6        56.6         0    kcal/mol
  Parameters determined: (-V/T = 2.0000000)
  k1 = 1.02480344  k2 = 1.23244364  
  s1 = 0.27877144  s2 = 0.28887416
  Kimball radii (bohr):
   P(Li 1s2)     Q(LiH)   R(exzentr.of H+)
   0.5607208   2.0066350   0.44516027
 
Gamess ,  Gaussian 98

Last changes December 19, 1998
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