PANDA: Predicting angle from nanoscale density analysis

The surface effects play a major role in various problems. In this paper, we present a new method for calculating contact angles in simulations based on density profiles of liquids in slit pores. We derive analytical expressions for the interface area, range of existence, and density profiles for different types of interface shapes in a rectangular slit pore with arbitrary contact angles. The algorithm is developed to determine the contact angle from the one-dimensional density profile, validated on synthetic and molecular dynamics data. The new method shows high accuracy and requires fewer hyperparameters than previous methods based on approximating the interface shape. The method’s weakness is sensitivity to the effective pore width, which will be addressed in future work by accounting for the molecular structure of the confined liquids. In the future, we plan to develop the proposed method: we will add automatic classification of surface type by molecular coordinates using neural networks and take into account the thickness of the near-wall layer of the wetting liquid.