We compute binding energies and root mean square radii for weakly bound
systems of N=4 and 5 identical bosons. Ground and first excited states of
an N-body system appear below the threshold for binding the system with N−1
particles. Their root mean square radii approach constants in the limit of weak
binding. Their probability distributions are on average located in
non-classical regions of space which result in universal structures. Radii
decrease with increasing particle number. The ground states for more than five
particles are probably non-universal whereas excited states may be universal