K6Cd4Sn3Se13:: A polar open-framework compound based on the partially destroyed supertetrahedral [Cd4Sn4Se17]10- cluster

K6Cd4Sn3Se13 forms in superheated water and has a polar open-framework structure that is based on an octahedral topological motif. It forms from the polymerization of a single [Cd4Sn3Se13](6-) cluster which formally derives from a [Cd4Sn4Se17](10-) via elimination of one [SnSe4](4-) anion. K6Cd4Sn3Se13 exhibits facile ion-exchange properties with suitably sized cations.