Semiempirical shell model masses with magic numberZ=126for translead elements withN<~126

A semiempirical shell model mass equation based on magic number $Z=126\mathrm{}$ and applicable to translead elements with $N<~126$ is presented. For $\alpha -\mathrm{d}\mathrm{e}\mathrm{c}\mathrm{a}\mathrm{y}$ energies the equation is shown to have a high predictive power and an rms deviation from the data of about 100 keV. The rms deviations for masses and other mass differences are between about 200 and 300 keV.