content_image/355910.jpg content_image/355914.jpg
<img src='content_image/355910.jpg'>

see that the parabola approximation to the change of energy with β$_{2}$ is acceptable. Fig.1(b) shows the value of b$_{2}$ as a function of the mass number. The crosses denote the results of the SkM* interaction for a number of nuclei along the β -stability line. We find that the dependence of b$_{2}$ on the mass number A can be reasonably well described by a formula 

<img src='content_image/355914.jpg'>

This form of mass dependence of b$_{2}$ is therefore adopted in the proposed mass formula and the optimal values of g$_{1}$ and g$_{2}$ are finally determined by the 2149 measured nuclear masses [6]. 

