The ground state geometries of some small clusters have been obtained via ab
initio molecular dynamical simulations by employing density based energy
functionals. The approximate kinetic energy functionals that have been employed
are the standard Thomas-Fermi (TTF) along with the Weizsacker correction
TW and a combination F(Ne)TTF+TW. It is shown that the functional
involving F(Ne) gives superior charge densities and bondlengths over the
standard functional. Apart from dimers and trimers of Na, Mg, Al, Li, Si,
equilibrium geometries for LinAl,n=1,8 and Al13 clusters have also
been reported. For all the clusters investigated, the method yields the ground
state geometries with the correct symmetries with bondlengths within 5\% when
compared with the corresponding results obtained via full orbital based
Kohn-Sham method. The method is fast and a promising one to study the ground
state geometries of large clusters.Comment: 15 pages, 3 PS figure