Onsite hybridization between Ce 4f and 5d states as the indicator of the transition from Kondo insulator to metallic state in CeRhSb

We discuss and determine the conditions under which a Kondo-insulator phase is stable. We show for CeRhSb that the dependence of the onsite hybridization energy VdfVdf between the Ce 5d and Ce 4f   states on the number of valence electrons or the unit cell volume is decisive for the hybridization Kondo gap formation. We also propose the method for determining the energy VdfVdf from the ab initio calculations. This approach supplies an accurate Kondo-insulator–metal transition in agreement with the recent experimental data.

► Proposed method of onsite hybridization calculation. ► Anomalous change of onsite hybridization with respect to doping. ► Anomalous change of onsite hybridization with respect to pressure. ► Cerium valence change at quantum critical point.