THOMAS-FERMI APPROACH TO NUCLEAR-MASS FORMULA .3. FORCE FITTING AND CONSTRUCTION OF MASS TABLE

The ETFSI method, developed in two earlier papers, is here used to construct a complete mass table. Since the method allows for interpolation both in the (N, Z) plane and with respect to deformations, without losing the characteristic shell-model fluctuations, it is some 2000 times faster than the HF-BCS method fora given force. The present table is calculated using a preliminary Skyrme-type force with delta-function pairing, fitted to a restricted data set of 491 spherical nuclei. The resulting rms error for all 1492 measured nuclei, spherical and deformed, with A greater-than-or-equal-to 36 is epsilon(rms) = 0.868 MeV, achieved with just 9 parameters. The main experimental trends in ground-state deformations are well followed. The symmetry coefficient of nuclear matter corresponding to our force is 27.5 MeV. Ways of rapidly improving the fit are indicated.