An inadequate over-parameterized Mössbauer spectral analysis for the mistaken detection of surface FeIV=O, in Nature Communications 16, 7642 (2025)

In disagreement with the claim in ref. 1 , the presence of surface Fe IV = O on FeS 2 , a synthetic pyrite, after the creation of surface sulfur vacancies followed by reaction with molecular oxygen, to form Fe … Fe@FeS 2 /O 2 is not supported by the reported 57 Fe transmission Mössbauer spectra. Herein, the Mössbauer spectral data have been reanalyzed with a simpler model involving fewer parameters – a reanalysis that agrees with the philosophy of Occam’s razor 2 . Further, the results presented are fully consistent with the known inadequacy of 57 Fe transmission Mössbauer spectroscopy for the characterization of any surface iron sites, such as Fe IV = O on FeS 2 .