In this book the focus is on the thermodynamic properties of a large nucleus of rhenium using N-interaction potential. Rhenium has been chosen because of its applications in technology, it's used in the engines of airplanes, missiles and high temperature thermo-couplers thus it may equally have an application at lower temperatures. The NN-interaction is used as a perturbation and general methods of quantum mechanics as well as many-body techniques have been used to calculate the energy, the heat capacity and the entropy