“…The bond valence sum (BVS) results for K + , Ba 2+ , Zr 4+ /Hf 4+ , F − , and Cl − ions are 0.97, 2.13-2.23, 4.00, 0.93-1.09, and 1.06 for KBZFC, and 0.98, 2.11-2.25, 4.12, 0.82-0.97, 1.08 for KBHFC, respectively (Table S2 †). 57 Related information for NCS halides with mixed uorine and chlorine atoms are summarized in Table S4, † and six of them belong to the tetrahedral system (I4: SbCl 3 F 2 , 58 − units, and Cl/Br atoms ll in the middle of the rings. 55,64 Nevertheless, the MF 7 units in KBZFC and KBHFC form the 0D structure that compensates for large anisotropy.…”