  approaches. We demonstrate that the Wigner regime can be reached using small
values of the confinement parameter. To obtain physical insight in our results
we analyze them with a semi-analytical model for two electrons. Thanks to
electronic-structure properties such as the one-body density and the
particle-hole entropy, we are able to define a path that connects the Wigner
regime to the Fermi-gas regime by varying the confinement parameter. In
particular, we show that the particle-hole entropy as a function of the
confinement parameter smoothly connects the two regimes. Moreover, it exhibits
a maximum that could be interpreted as the transition point between the
localized and delocalized regimes.
