Pr16Mo21O56
Résumé
The structure of hexadecapraseodymium henicosamolybdenum hexapentacontaoxide, Pr16Mo21O56, is isotypic with other rare earth representatives of formula type RE 16Mo21O56 (RE = La, Ce, Nd). It is characterized by Mo10O18 iO8 a units (where i = inner and a = apical O atoms) containing bioctahedral Mo10 clusters and octahedral MoO6 units that share some of their O atoms to form the Mo-O framework. The two independent Mo10 cluster units are centred at Wyckoff positions 2b and 2c and have point-group symmetry An external file that holds a picture, illustration, etc. Object name is e-67-00i34-efi1.jpg. The Mo atom of the MoO6 unit is likewise situated at an inversion centre (2d). The eight crystallographically different Pr3+ cations occupy irregular voids in the framework with coordination numbers to the O atoms varying between 8 and 11.