Molecular string representations, such as DeepSMILES and SELFIES , enable processing chemical structures using models like transformers that are designed to process sequential data. Recently, a study investigated the performance of transformers on different tasks using SMILES, DeepSMILES, and SELFIES. The amount of returned invalid chemical structures could be decreased when using DeepSMILES and especially SELFIES compared to SMILES, although the overall best performance was achieved using SMILES .