function of the number of nucleons, the shell correction takes care of the shell fluctuations of the binding energy which is missing from the macroscopic model. Shell fluctuations are present in any microscopic model. E.g. the shell correction can be calculated from sin- gle particle energies of self-consistent Hartree-Fock and relativistic mean filed calculations [17, 18]. In Ref. [18] shell correction calculated on the single particle energies was used to generate a smooth energy from the result of these microscopic calculation and the typi- cal phenomenological parameterization of the microscopically calculated macroscopic energy terms were analyzed. In the present work we use the simplest i.e. the independent particle shell model to generate the single particle energies in a phenomenological nuclear potential for the sake of simplicity only, since the smoothing procedure could be tested equally well on the result of this simple model. In this model we treat neutrons and protons separately. In this case the shell correction is the sum of the shell corrections δE$_{τ}$ ( N$_{τ}$ ) calculated for neutrons: τ = ν with N$_{ν}$ = N and for protons τ = π with N$_{π}$ = Z . In what follows we shall discuss the calculation of the shell correction δE$_{τ}$ ( N$_{τ}$ ) for a sort of nucleons only. The shell correction can be estimated as the difference of the shell model binding energy E τ sp and its smoothed counterpart ˜ E τ calculated also in the shell model. Here the shell model binding energy is a sum of the single particle energies E τ j of the lowest energy orbits, from E τ 1 until the Fermi-level. In the sum above we can take into account the n$_{i}$ -fold degeneracies of the shell model orbits and use only the different single particle energies denoted by e τ i The key quantity of the MM model is the smoothed energy ˜ E τ therefore, we have to give a unique definition for calculating it unambiguously. If we have the bound single particle δE ( N, Z ) = ∑ τ = ν,π δE$_{τ}$ ( N$_{τ}$ ) = δE ( N ) + δE ( Z ) (2) δE$_{τ}$ = E τ sp − ˜ E τ . (3) E τ sp = N τ ∑ j =1 E τ j (4) E τ sp = ∑ i n$_{i}$ e τ i . (5) 4