We also found, critically, that the normalization can not only affect model performance but can heavily affect the feature ranking, introducing an important caveat for future interpretability studies: Carbone et al. and Zheng and Chen et al. both normalized each spectrum to the maximum value of the spectrum, and we compared their max-normalization to post-edge normalization, with spectra normalized to the value of absorption 50 eV after the rising edge value (which FEFF 9 performs by default). While normalization to the peak constrains the range of the spectrum, there is no clear physical basis for normalization to that value. For mean nearest-neighbor distance and Bader charge, the relative importances of a 0 and a 1 , a 2 swung based on the normalization decision, highlighting the importance of physically relevant normalization.