In this work we have presented the first application of the separable, finite-range pairing interaction of the Gaussian form together with the non-relativistic functional of the Skyrme type. This interaction was used to determine both the ground-state Hartree-Fock-Bogolyubov solutions and Quasiparticle-Random-Phase-Approximation monopole strength functions in semi-magic nuclei. Results were systematically compared with those pertaining to the standard zero-range pairing interaction.
From the monopole strength functions, we extracted the finite-nucleus
incompressibilities and compared them to experimental data. It turned
out that neither zero-range nor separable pairing effects were able
to describe the low values of incompressibilities measured in tin,
relative to the high value measured in 
Pb. By changing the
infinite-matter incompressibility, one can certainly describe either
the tin or lead values; however, the high difference thereof remains
unexplained.
We have also performed adjustments of the liquid-drop formula to microscopically calculated incompressibilities, and we found that (i) such a formula is able to describe microscopic results very well, and (ii) the volume liquid-drop term is significantly higher than the infinite-matter incompressibility determined for a given functional.