Table shows the scoring system for atoms of a representative small molecule. The possible value range of SPS starts at 0 and has no upper limit. However, in order for the SPS to be directly comparable between diverse structures, molecular size needs to be taken into consideration. The SPS can be easily and reliably normalised in respect to size by dividing the total score by the total number of heavy atoms (𝑎) in a given molecule and the resulting normalised score is referred to as nSPS (eq. 4). The SPS and nSPS computations were implemented as a Python script based on the RDKit software, calculating the scores using simplified molecular-input line-entry system (SMILES) as input. 𝑛𝑆𝑃𝑆 =