An Appraisal of the Understanding Pressure Effects on Structural, Optical, and Magnetic Properties of CsMnF4 and Other 3dn Compounds

A recent theoretical study of CsMnF4 under pressure presents conclusions on its structural, optical, and magnetic behavior that conflict with established experimental evidence. Crucially, that work omits key prior experimental results on CsMnF4 and related Mn3+ fluorides under pressure. This commentary examines the resulting discrepancies, arguing that omissions of this data undermine the theoretical estimates and methodological validity. This paper provides a critical overview centered on two main points: the contested nature of the pressure-induced high-spin to low-spin transition observed in CsMnF4 at ~37 GPa, and a detailed discussion of Jahn–Teller physics in this archetypal system. By reconciling the existing literature with the new theoretical claims, this work aims to clarify the high-pressure behavior of CsMnF4. A thorough analysis on the spectroscopic and magnetic properties of Mn3+ fluorides is included to support this commentary.