Alkalimetallbismutide ABi und ABi2 (A = K,Rb, Cs) — Synthesen,Kristallstrukturen, Eigenschaften

Alkali Metal Bismuthides ABi and ABi₂ — Synthesis, Crystal Structure, Properties The Zintl phases ABi (A = K/Rb/Cs; monoclinic, space group, P2₁/c, a = 1422.3(2)/1474.2(2)/1523.7(3), b = 724.8(1)/750.2(1)/773.7(1), c = 1342.0(2)/1392.1(2)/1439.9(2) pm and β = 113.030(3)/113.033(2)/112.722(3)°, Z = 16) crystallize with the β‐CsSb structure type containing chains of two‐connected Bi atoms. Hence, and according to calculated electronic structures, they are semiconductors with small band gaps of approx. 0.5 eV. In contrast, the compounds ABi₂ (A = K/Rb/Cs; cubic, space group Fd3¯m, a = 952.1(2)/962.4(8)/972.0(3) pm, Z = 8) belong to the Laves phases, showing a typical metallic electrical conductivity and no band gaps.