A new method is proposed to describe masses of nuclei belonging to single a major shell. It is based on a global formula for the macroscopic part of the nuclear mass while the remaining (shell + deformation) part is considered in the context of the interacting boson model. The framework enables a simultaneous calculation of spectra and binding energies.

PACS numbers: 21.10.Dr, 21.60.Gx, 21.10.Re