Method of calculations

The CHF calculations were performed using the code HFODD (v1.75) [26,27] with the interaction SLy4 [31]. The accuracy of the harmonic oscillator (HO) expansion depends on the frequencies ($\hbar\omega_x$, $\hbar\omega_y$, and $\hbar\omega_z$) of the oscillator wave functions and the number $M$ of the HO states included in the basis. The basis set includes the lowest $M$ states with energies given by

$$\varepsilon_{n_x,n_y,n_z} = \hbar \omega_x (n_x + \frac 12) ... ... \omega_y (n_y + \frac 12) + \hbar \omega_z (n_z + \frac 12).$$ (29)

An axially symmetric basis ( $\omega_x=\omega_y$) with the deformation $q=\omega_x/\omega_z=1.81$, oscillator frequency $\hbar\omega_0=41A^{-1/3}$ MeV, and value of $M=296$ was used in all the CHF calculations. This basis provides sufficient numerical accuracy for the physical observables of interest [32].

The CRMF calculations were performed using the computer code developed in Refs. [33,34,12]. An anisotropic three-dimensional harmonic oscillator basis with deformation ( $\beta_0=0.4,\,\gamma=0^{\circ}$) has been used in the CRMF calculations. All fermionic states below the energy cutoff $E^{\mbox{\scriptsize cut-off}}_F \leq 11.5\hbar\omega^F_0$ and all bosonic states below the energy cutoff $E^{\mbox{\scriptsize cut-off}}_B \leq 16.5\hbar\omega^B_0$ were used in the diagonalization and the matrix inversion. This basis provides sufficient numerical accuracy. The NL1 parametrization of the RMF Lagrangian [35] has been used in the CRMF calculations. As follows from our previous studies, this parametrization provides reasonable s.p. energies for nuclei around the valley of $\beta$-stability [8,36].