PNNL

Abstract

In the comments made by Manceau1 on the study by Sassi and Rosso,2 some concerns were raised regarding the potential for the structure theoretically found and identified as ferrihydrite (Michel model3 ) to be hydromaghemite. Here, we address these concerns by showing that the structure theoretically generated cannot be unambiguously compared to hydromaghemite. Many of the concerns raised are, in fact, oblique to the given study. Notwithstanding, we reiterate clearly stated methodological details and caveats regarding the theoretical structural search performed, which disallow for the hydromaghemite prospect to manifest. We furthermore highlight the scholarly importance of examining experimental X-ray diffraction (XRD) and pair distribution function (PDF) of synthesized ferrihydrite samples from a variety of independent sources, as embodied in a broader set of relevant literature.