Perturbation calculations for the Schroedinger equation with a bistable potential

The renormalized hypervirial perturbation method is used to compute the energy levels for a bistable potential of the form V(x)=λ2((α2/8(cos h(4λx)-1)-α(β+1)cos h(2λx)), depending on 3 perturbation parameters λ, α, β. Eigenvalues for different sets of the parameters and state number n are listed in tables. It is found that the renormalized series method works well even for large values of α and β. The results agree with those produced by finite difference technique. 3 tabs., 6 refs