The Crystal Structures of CsTh6F25 and NaTh3F13

Two new alkali thorium fluorides have been synthesized hydrothermally and structurally characterized. The structures of CsTh 6 F 25 and NaTh 3 F 13 are each described in space group P 6 3 /mmc (No. 194) with a = 8.3507(12) and c = 16.914(3) Å, and a = 8.2570(12) and c = 16.891(3) Å, respectively. Both structures exhibit a framework structure containing pores, unlike most of their alkali metal thorium fluoride analogs. The significant structural difference between the two compounds, however, is the arrangement of the alkali metal within the pores formed in the framework. Accordingly the pores exhibit differing degrees of distortion depending on their contents. Graphical Abstract Two new alkali thorium fluorides, CsTh 6 F 25 and NaTh 3 F 13 , have been synthesized hydrothermally and found to crystallize in space group P 6 3 /mmc (No. 194) with both having an interesting structural difference in the contents of the pores formed from their framework structures.