Citation: Siidra, Oleg I.; Charkin, Dmitry O.; Kovrugin, Vadim M.; Borisov, Artem S. (2021). K(Na,K)Na~2~[Cu~2~(SO~4~)~4~]: a new highly porous anhydrous sulfate and evaluation of possible ion migration pathways. Acta Crystallographica Section B, 77, pp. 1003-1011.