  In this paper we continue our development of a dimensional perturbation
theory (DPT) treatment of N identical particles under quantum confinement. DPT
is a beyond-mean-field method which is applicable to both weakly and
strongly-interacting systems and can be used to connect both limits. In a
previous paper we developed the formalism for low-order energies and excitation
frequencies. This formalism has been applied to atoms, Bose-Einstein
condensates and quantum dots. One major advantage of the method is that N
appears as a parameter in the analytical expressions for the energy and so
results for N up to a few thousand are easy to obtain. Other properties
however, are also of interest, for example the density profile in the case of a
BEC,and larger N results are desirable as well. The latter case requires us to
go to higher orders in DPT. These calculations require as input zeroth-order
wave functions and this paper, along with a subsequent paper, addresses this
issue.
