Two cases of the TCO potential connement are also displayed in Figs. 6(b) and 6(c), the former corresponding to a symmetric double well (ε = 0) and the latter to the case when the right well is strongly higher by ε = 2.0 meV. The corresponding three lowest-energy eigenfunc-tions are also displayed in the triad of Figs. ) and the triad of Figs. 6(g-i) for these two values of ε, respectively. It is seen that the eigenfunctions in Figs. ) preserve the parity around the origin and extend over both wells (as was to be expected for a symmetric double well), whereas those in Figs. ) are restricted within the left well (as was to be expected again for a highly tilted double well) .