First column shows the heatmap of the eigenfunction of FEM (the first column) and the other columns show the heatmaps of the relative error of GIPMNN (the second column), PC-GIPMNN (the third column), and DRM (the fourth column) for the 2D IAEA benchmark problem. However, by enforcing the interface conditions, PC-GIPMNN outperforms GIPMNN and DRM, as shown in the third column.