The selection of hydrogen bonding criterion can impact the computed EC value. However, time-averaged water density information is unaffected by this choice. Thus, incorporating both hydrogen bonding and density information will provide a data representation that is robust to particular choices of criterion.As such, we represent the SAM surface as a 2D manifold M and treat the time-averaged water density at the interfacial layer as a continuous function on the manifold f : M → R as shown in Figure . The manifolds are constructed by binning water molecule positions at the interfacial layer in a 20 × 20 grid, where each grid point accounts for 0.1 nm 2 area on the surface of a SAM over the period of 800 simulation time steps. The accumulated bin data are then averaged to obtain a continuous water density function for our surface manifold M. This representation matches the representation of Kelkar and co-workers used as input to a CNN to allow for direct model comparison. We performed a manifold filtration to quantify spatial density fluctuations in water at the SAM surface with an EC curve. We recall that the EC curve is the set of paired filtration thresholds k i and EC values χ i of the filtered sublevel sets M k i . The filtration thresholds k i represent water densities given in units of molecules/nm 2 .