Über Oxoindate der Alkalimetalle Zur Kenntnis von Rb2In4O7

Oxoindates of Alkali Metals. On Rb₂In₄O₇ The hitherto unknown Rb₂In₄O₇ crystallizes trigonal with a = 5.62₈, c = 7.34₀Å, c/a = 1.30, z = 1 in thespacegroupD–P3 1m. The atomic parameter see text. The structure derives from a cubic closest packing of O²- with In³⁺ in 1/9 of the tetra-hedral and 2/9 of the ovtahedral sites. Rb substituates 2/3 of the O²- ions of each third layer. The MADELUNG Part of Lattice Energy is calculated and discussed.