  The nuclear landscape has been investigated within the triaxial relativistic
Hartree-Bogoliubov theory with the PC-PK1 density functional, and the
beyond-mean-field dynamical correlation energies are taken into account by a
microscopically mapped five-dimensional collective Hamiltonian without
additional free parameters. The effects of triaxial deformation and dynamical
correlations on the nuclear landscape are analyzed. The present results provide
the best description of the experimental binding energies, in particular for
medium and heavy mass regions, in comparison with the results obtained
previously with other state-of-the-art covariant density functionals. The
inclusion of the dynamical correlation energies plays an important role in the
PC-PK1 results. It is emphasized that the nuclear landscape is considerably
extended by the PC-PK1 functional in comparison with the previous results with
other density functionals, which may be due to the different isovector
properties in the density functionals.
