Fig. 10
From: A beginner’s approach to deep learning applied to VS and MD techniques
Schematic representation of radial and angular ACSFs [153]. In this example, the ACSFs are defined for the central atom (red circle) of the system (blue box). A cut-off radius C (blue dotted line) defines which neighboring atoms (green circles) are included in the atomic environment of the central atom, and thus in the calculation of the ACSFs. The radial ACSF is the sum of the products of Gaussians and cut-off functions for all atoms within the atomic environment, with the Gaussians describing the distances R between the central atom and each neighboring atom (red arrows), whilst the cut-off functions ensure decay to zero in value and slope towards the cut-off radius. The angular ACSF is the sum of the products of the cut-off functions and the angles A between the central atom and pairs of two neighboring atoms (green curved arrows)