Crystal chemistry of AB 2X 4 (X = S, Se, Te) compounds

Abstract

An attempt is made to correlate the crystal structures of ternary chalcogenides of composition AB 2X 4 with the cationic radius ratio and a pseudo force-constant involving their electronegativities. The resultant diagram adequately resolves structures based on the types K 2SO 4, monoclinic, olivine, MnY 2S 4, Th 3P 4, and CaFe 2O 4 but structure types based on spinel, Cr 3Se 4, and Ag 2HgI 4 are not resolved. Crystal chemical arguments are used to explain these observations and to advance reasons for the successes and failures of this method for predicting structure types.