  We propose a newly optimized nonlinear point-coupling parameterized
interaction, PC-L3R, for the relativistic Hartree-Bogoliubov framework with a
further optimized separable pairing force by fitting to observables, i.e., the
binding energies of 91 spherical nuclei, charge radii of 63 nuclei, and 12 sets
of mean pairing gaps consisting of 54 nuclei in total. The separable pairing
force strengths of proton and neutron are optimized together with the
point-coupling constants, and are justified in satisfactory reproducing the
empirical pairing gaps. The comparison of experimental binding energies
compiled in AME2020 for 91 nuclei with the ones generated from the present and
other commonly used point-coupling interactions indicates that the
implementation of PC-L3R in relativistic Hartree-Bogoliubov yields the lowest
root-mean-square deviation. The charge radii satisfactory agree with
experiment. Meanwhile, PC-L3R is capable of estimating the saturation
properties of the symmetric nuclear matter and of appropriately predicting the
isospin and mass dependence of binding energy. The experimental odd-even
staggering of single nucleon separation energies is well reproduced. The
comparison of the estimated binding energies for 7,373 nuclei based on the
PC-L3R and other point-coupling interactions is also presented.
