  Starting from the Argonne V18 nucleon-nucleon (NN) interaction and using the
Unitary Correlation Operator Method, a correlated interaction v_UCOM has been
constructed, which is suitable for calculations within restricted Hilbert
spaces. In this work we employ the v_UCOM in Hartree-Fock, perturbation-theory
and RPA calculations and we study the ground-state properties of various
closed-shell nuclei, as well as some excited states. The present calculations
provide also important feedback for the optimization of the v_UCOM and valuable
information on its properties. The above scheme offers the prospect of ab
initio calculations in nuclei, regardless of their mass number. It can be used
in conjunction with other realistic NN interactions as well, and with various
many-body methods (Second RPA, QRPA, Shell Model, etc.).
