Gitterkonstanten und Ionenradien für Pyrochlore CsMIIMIIIF6

Lattice Constants and Ionic Radii of Pyrochlores CsM^IIM^IIIF₆ From observed lattice constants a₀ of 30 cubic pyrochlores CsM^IIM^IIIF₆ (M^II = Mg, Ni, Cu, Zn, Co, Mn; M^III = Ga, Cr, Fe, V, Ti) balanced values a_c were calculated, which deviate in average less than 0.1% from the observed ones. Radii r_c of the M(II) and M(III) ions are evaluated from the balanced values a_c by means of an empiric equation; they reproduce the lattice constants a₀ equally well. By analogy derived radii r_II and r_III from additional pyrochlores CsM^IIM^IIIF₆ are given and discussed in comparison with tabulated radii and observed M? F distances.