This data set contains the numerical calculations that lead to figures 2 and 4 of the article. For figure 2 (First data set), numerical calculations are compared with the analytical model given by equation 24. The numerical calculations are computed using the exact form of the potential, equation 21, and are given by the second and third column of the data set. While the anlaytical model is obtained using the approximation given by equation 24, and is given by the fourth column in the data set. The first column represents the spatial coordinate. It is associated with the domain wall width. For figure 4 (Second data set), the band structure of a periodic array is calculated using equation 25. The first column corresponds to the wave vector, the following columns correspond to the first, second, etc. band. Both data sets, apart from the analytical calculation, were calculated using Pyhton code.