A local formula of binding energy for heavy and superheavy nuclei has very recently been proposed [Dong and Ren, Phys. Rev. C 72, 064331 (2005)]. In this paper, the limit of the predictive ability of this local formula is investigated. It is found that the neutron-proton correlations should be considered when higher precision is required. On the one hand, we introduce a new term $|N-Z-50|/A$, and on the other hand we consider the different strengths of proton-proton, neutron-neutron, and neutron-proton pairing correlations. For the first time, the standard deviation $\sqrt{{\sigma }^2}$ of the binding energies for 117 nuclei with $Z⩾90$ and $N⩾140$ is reduced to 0.105 MeV. The α decay energies $Q_{\alpha }$ and half-lives $T_{\alpha }$ of nuclei with $Z=102\text{−}118$ are reproduced quite well. The proton drip line of superheavy elements from Md ($Z=101$) to Ds ($Z=110$) are predicted.

• Received 9 March 2008

DOI:https://doi.org/10.1103/PhysRevC.77.064310