A simple approximation to the nuclear kinetic energy density

A new functional of the density and its derivative is proposed for the kinetic energy density and the corresponding Euler equations are solved. Comparisons with Hartree-Fock results show close agreement, particularly for the shape of the density at the surface, for heavy as well as for light nuclei. The surface of a system of 5000 nucleons is studied as an approximation to a semi-infinite medium. The dynamical properties of this functional are tested in the case of the giant monopole resonance and are satisfactory when compared to more microscopic treatments. (orig.)