Twinned caesium cerium(IV) pentafluoride

Abstract

Single-crystals of CsCeF5were synthesized hydrothermally. The crystal under investigation was twinned by pseudo-merohedry with a twofold rotation around thecaxis as an additional twinning operation. The crystal structure is built of layers of distorted edge- and corner-sharing CeF8square-antiprisms. The Cs+cations are located between the layers and exhibit coordination numbers of nine. Upon compression, CsCeF5undergoes an irreversible phase transition at about 1 GPa.