In this chapter, we shall investigate the interaction of a non-relativistic particle of mass m and energy E with various so-called central potentials, V(r) , where r is the radial distance from ...In this chapter, we shall investigate the interaction of a non-relativistic particle of mass m and energy E with various so-called central potentials, V(r) , where r is the radial distance from the origin. It is, of course, most convenient to work in spherical coordinates— r , θ , ϕ —during such an investigation.. Thus, we shall be searching for stationary wavefunctions, ψ(r,θ,ϕ) , that satisfy the time-independent Schrödinger equation.