Özet:
The Hubert space L2(ℝ3), to which the wavefunction of the three-dimensional Schrödinger equation belongs, has been replaced by L2(Ω), where Ω is a bounded region. The energy spectrum of the usual unbounded system is then determined by showing that the Dirichlet and Neumann problems in L2(Ω) generate upper and lower bounds, respectively, to the eigenvalues required. Highly accurate numerical results for the quartic and sextic oscillators are presented for a wide range of the coupling constants.