Implications of Invalid Conversions between Crystal-Field Parameters and Zero-Field Splitting Ones Used in Superposition Model

The methodology used in recent study of the zero-eld splitting parameters of Cr 3+ ions at various orthorhom- bic symmetry sites in LiKSO4 by Pandey and Kripal is critically commented on.We argue that the crystal eld parameters, B kq , in the Wybourne notation, which were calculated using the superposition model for Cr 3+ ions in LiKSO4, may only be converted into the crystal eld parameters in the Stevens notation.Regrettably, the authors have also converted the latter parameters supposedly into the zero-eld splitting parameters D and E in the conventional notation.Such direct conversions are fundamentally incorrect and constitute factual invalid usage of the conversion relations between the crystal eld (ligand eld) parameters and the zero-eld splitting ones.The cases of an implied usage of the invalid conversion relations between the crystal eld parameters and the zero-eld splitting parameters occurring in recent literature are also outlined.Pandey and Kripal have found the zero-eld splitting parameters theoretically evaluated in this way to be in good agreement with the experimental values.However, the faulty methodology renders the conclusion that Cr 3+ ions enter into the LiKSO4 lattice at the substitutional K + sites unjustied.Several other conceptual problems arising from misinterpretations of the crucial notions identied therein are also discussed and claried.