  General expression for the thermodynamic potential of the model of
semi-infinite jellium is obtained. By using this expression, the surface energy
for infinite barrier model is calculated. The behavior of the surface energy
and of chemical potential as functions of the Wigner-Seitz radius and the
influence of the Coulomb interaction between electrons on the calculated values
is studied. It is shown that taking into account the Coulomb interaction
between electrons leads to growth of the surface energy. The surface energy is
positive in the entire area of the Wigner-Seitz radius. It is shown that taking
into account the Coulomb interaction between electrons leads to a decrease of
the chemical potential.
