I am a little confused how one can find a wave function by using WKB approximation? I do know the oscillation frequency $$\omega = {2E\over h}Re(<L|R>)$$$$\Omega ~=~ {2E\over h}{\rm Re} \langle L|R \rangle~=~ {E\over \pi\hbar}{\rm Re} \langle L|R \rangle, $$
where L$L$, R$R$ are the eigenstate of the left and right well.
However, the key of finding this inner product is a pain to me, can someone teach me through it? Appreciated in advance!