Consider a potential that depends only on the radial direction \(r\) in a three-dimensional space, \(V(r)\), with \(V(r\) such that \(\rightarrow \infty)=0\) while \(V(0)=-V_{0}<0\) and \(V_{\max }=\max _{r} V(r)=V_{1}>0\), reached at \(r=r_{1}\), and there is a unique solution \(r_{0}\) to the equation \(V\left(r_{0}\right)=0\). Describe the spectrum of the system in the various energy regimes.