  The recent developments of radioactive nuclear beams has opened up the
possibility of exploring a wide variety of nuclei far from the valley of
beta-stability. Of late several theoretical studies have come up in the past
for describing nuclei in these exotic region. Extension of traditional shell
model techniques to explain the exotic feature in the structure of these nuclei
such as, formation of neutron halo large r.m.s radii, soft dipole resonances
etc have confirmed the necessity to modify the single particle shell model
potential when dealing with nuclei far from stability. The ground state nuclear
structure properties of 4Be11 have been calculated in the framework of shell
model using analytically soluble mean field potential given by Ginocchio. The
potential is highly versatile in nature and depends on four parameters, which
define its depth, range and shape. Potential parameters, which generate highly
diffuse shape, account for the small binding and halo structure of the valence
neutron in 4Be11. The problem of ground state parity inversion is also
addressed.
