Finite-well bound-state node sequence
= Finite-well bound-state node sequence
For a symmetric one-dimensional <finite square well>, nondegenerate <bound states> alternate even and odd <parity>, starting with an even <ground state>. The $n$th state counted from zero has $n$ interior <nodes>. Outside the well, it decays with inverse <length> $\sqrt{2m(U-E_n)}/\hbar$. Matching both the <wavefunction> and its first <derivative> at a finite step distinguishes it from the infinite-well approximation.