Figure 6.

Visualization of the activations of different materials in ElemNet. Each frame shows a 2D projection (using PCA) of the activations of different materials in several layers of ElemNet, which shows which materials have similar representations. The upper row shows the activations of different elements, where each point is a different element and is colored by the group number. The second row shows the activations of AB compounds formed of group I and II metals combined with S (group VI) or Cl (group VII). We note that elements from the same group in the periodic table, such as alkali metals, are clustered together in the early layers of the network, and that later layers reflect properties related to combinations of elements (e.g., charge balance).