We calculate the ground state and a class of zero orbital angular momentum (L=0) vibrationally excited state energies for Ne-N and Ar-N clusters using an adiabatic hyperspherical representation to solve the nuclear Schrodinger equation. The Schrodinger equation in the hyperangular coordinates is solved for a sequence of fixed hyperradii by diffusion Monte Carlo techniques, which determines the lowest effective potential curve. We monitor structural properties such as the pair and angle distribution as a function of the hyperspherical radius. These structural studies allow us to identify configurational changes as the N atom cluster fragments into an (N-1)-atom cluster plus an atom. We also determine separately the ground state of the full 3N-dimensional nuclear Schrodinger equation for the ground state, and compare the resulting structural properties with those calculated in the adiabatic hyperspherical approximation.