Chemprop incorporates four bond features from RDKit, represented as one-hot In Graphormer-IR, the same bond embeddings are used across all models, except for the aromaticity encoding, which is omitted as it is redundant due to the bond type feature. All bond features are listed in table , with associated descriptions and domains. Additionally, a custom descriptor for connections to the global phase node (i.e., connected or not) is introduced, on which we elaborate in the Phase Encoding section below. Since we have 4 bond encodings that have 4, 2, 2, and 6 classes respectively, we can consolidate the edge encoding using combinatorics into a single description of 96 classes (4x2x2x6). This means that every edge in the graph is described by an integer from 0 to 95, where each number corresponds to a specific combination of the bond encodings.