## ABSTRACT

This chapter explores that the mean-field picture can also lead to the breaking of rotational symmetry. A good approximation to the mean field wave functions can be found by parameterizing the one-body field with just a few well-chosen variables, such as its depth, radius, and surface thickness. The parametrized independent-particle model has advantages and disadvantages when viewed as an approximation to mean field theory. In general there is no reason to believe that the Hartree-Fock mean field should be spherically symmetric. In order to study this possibility, the independent-particle model may be generalized to have a deformed potential. The independent-particle approximation to the mean field picture gives a good account of the shapes of nuclear ground states, which are only moderately deformed from the spherical shape. The chapter concludes that the mean field picture is capable of describing important features of both small and large deformations of the nuclear shape.