Ternary compound

In inorganic chemistry and materials chemistry, a ternary compound or ternary phase is a chemical compound containing three different elements.

While some ternary compounds are molecular, e.g. chloroform (HCCl₃), more typically ternary phases refer to extended solids. Famous example are the perovskites.

Binary phases, with only two elements, have lower degrees of complexity than ternary phases. With four elements, quaternary phases are more complex.

The number of isomers of a ternary compound provide a distinction between inorganic and organic chemistry: "In inorganic chemistry one or, at most, only a few compounds composed of any two or three elements were known, whereas in organic chemistry the situation was very different."