  The ordering of N equally charged particles (-e) moving in two dimensions and
confined by a Coulomb potential, resulting from a displaced positive charge Ze
is discussed. This is a classical model system for atoms. We obtain the
configurations of the charged particles which, depending on the value of N and
Z, may result in ring structures, hexagonal-type configurations and for N/Z~1
in an inner structure of particles which is separated by an outer ring of
particles. For N/Z<<1 the Hamiltonian of the parabolic confinement case is
recovered. For N/Z~1 the configurations are very different from those found in
the case of a parabolic confinement potential. A hydrodynamic analysis is
presented in order to highlight the correlations effects.
