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Free keywords:
intermetallic phases; half-heusler compound; electronic; structure
Abstract:
18-electron compounds REML (RE = rare earth metal; M = Cu, Ag, Au; L = Ge, Sn) can adopt either the stuffed graphite-like (P6(3)mc) or the stuffed diamond-like (F (4) over bar 3m) structure. To understand why one structure is favored over the other, we carried out density functional theory electronic structure calculations for a number of REAuSn compounds. The stuffed graphite-like and stuffed diamond-like structures of an 18-electron compound REAuSn are quite similar in their electronic structures with the Au atoms best described as existing as anions. The diamond-like REML becomes possible only when the RE3+ ion is small and the M-L bond is long.
