Mixed cations and structural complexity in (Eu(1-x)Ca(x))(4)In(3)Ge(4) and (Eu(1-x)Ca(x))(3)In(2)Ge(3)--the first two members of the homologous series A(2[n+m])In(2n+m)Ge(2[n+m]) (n, m = 1, 2, ...infinity; A = Ca, Sr, Ba, Eu, or Yb).

Reported are the synthesis and the structural characterization of two members of a new homologous series of polar intermetallic compounds, which exist only with mixed alkaline-earth and rare-earth metal cations. Crystals of (Eu(1-x)Ca(x))(4)In(3)Ge(4) (0.35(1)