The neutron and proton separation energies and mean square charge radi
i are evaluated within the Woods-Saxon plus BCS model for even-even nu
clei with 40 less than or equal to A less than or equal to 256. The va
rious parametrizations of the Woods-Saxon potential are examined. The
improved values of the constants of the central part of Woods-Saxon po
tential are determined from a least-square adjustment to the existing
experimental data.