The structures of the ''pure'' compounds K2ZnCl4 and Cs2ZnCl4 are well
-known. We have studied the occupation probability in host sites for s
olid solutions crystals KxCs2-xZnCl4 and specially for KCsZnCl4. We sh
ow that the K substitution in the Cs sites is not random. We also corr
elate our structural results with the evolution of the physical proper
ties of the crystal KCsZnCl4.