“…The Morse-Smale complex, in particular, encodes the gradient flow features of a scalar function, including those of interest in porous media: minima, basins, valley lines, 1-saddles, and the interfaces between basins. These same topological features form the basis for the analysis of: electronic potentials in quantum chemistry [3,34], the filamentary and dark matter structure in cosmology [40]; the formation of bubbles in mixing fluids [29]; the core structure of open cell foams [20,35]; lithium diffusion pathways [21,22]; and many others [6,7,37]. For extracting the pore structure for porous materials, Homberg et al [24,25] described computing the pores and throats of porous materials in terms of the Morse complex of the distance function.…”