Figure 3.

The schematic diagram shows a grid point as a cube of size 200 nm on each dimension in the 3-dimensional space. In this cube, we put a single dyad. Assuming that the width of the dyad is 300 nm, we model the efflux of calcium flowing into 4 adjacent grid points, and it is equally split into 4 parts. The grid location is given by the coordinate (i,j,k).