The isostructural title compounds were prepared from the elements in the stoichiometric ratio at 700
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C under exclusion of air. ZrSbTe and HfSbTe crystallize in the orthorhombic space group
Immm, NbPStype,
Z = 4, with
a = 3.91171(6) Å,
b = 5.80593(8) Å,
c = 13.4630(3) Å,
V = 305.760(6) Å
3 forZrSbTe, and
a = 3.86757(8) Å,
b = 5.75115(9) Å,
c = 13.4422(3) Å,
V = 298.995(6) Å
3 for HfSbTe.The transition metal atoms are surrounded by four Sb and four Te atoms in the form of a bicappedtrigonal prism. Two such prisms are joined via the third rectangular face, yielding a metal-metal bondacross this face. The structures bestow with their unusual rectangular planar Sb layers exhibitingnonclassical Sb-Sb bonding. The distortion within the layers, reflected in the formation of alternatingSb-Sb distances along the
b-axis, occurs with the formation of a band gap within the Sb bands. However,both compounds are metallic conductors with a small Seebeck coefficient, a consequence of a partialoverlap of metal and Te states caused by the metal-metal bond.