Miedema’s model revisited: The parameter phi* for Ti, Zr, and Hf

Failures of Miedema’s model to predict enthalpies of formation for binary Zr-based compounds are attributed to the original choice of the parameter for electronegativity, phi*=3.45 V, for Zr. By refinement procedures based on (1) ab initio enthalpies of formation, (2) reliable calorimetric data for the compounds, and (3) data for elemental metallic Zr we suggest that phi*=3.62 V is a reasonable choice. With this refined value, the revised enthalpies of formation for Zr-based compounds obtained by the Miedema model are substantially improved. The procedures applied possibly open up a new avenue for improving the reliability of Miedema’s model by critically assessing the parameter phi* also for other problematic cases, and without changing the original model.