 For 1-, 2- and 3-dimensional spaces potential wells do always scatter waves, no matter how small their potentials are, what their signs are or how limited their sizes are.For a particle in a one-dimensional lattice, like the Kronig–Penney model, it is possible to calculate the band structure analytically by substituting the values for the potential, the lattice spacing and the size of potential well.For two and three-dimensional problems it is more difficult to calculate a band structure based on a similar model with a few parameters accurately.