Heusler alloys

Place X, Y and Z on the four fcc sublattices, compare site arrangements, and check valence-electron rules. The model is a proposed ordering, not a relaxed or confirmed structure.

Half-Heusler with 18 valence electrons — the standard example of a closed-shell, semiconducting count (thermoelectric studies). Reference notes and lattice parameters are approximate summaries — check the primary literature before citing.