Here, we analyze our explanation dataset to investigate how the similarity of the explanation values for a pair of atoms (or bonds) in the same molecule depends on their closeness. For each pair of atoms (or bonds), the closeness is measured by their topological distance, the shortest path (number of edges) between them in the molecular graph. Then the similarity of pairs of explanations at a certain topological distance is measured in two ways. The first approach is the topological autocovariance ACL between atoms (or bonds) at a topological distance L. The topological autocovariance (Eq. 3) is the conditional expectation E of the product of the mean-subtracted explanation values for two atoms (or bonds) i and j in a molecule M, where the topological distance 𝑑 is L.