isomorphˈism noun

1. Similarity in shape or structure in unrelated forms (biology)
2. Close similarity in crystalline form combined with similar chemical constitution (crystallography)
3. A one-to-one correspondence between the elements of two or more sets and between the sums or products of the elements of one set and those of the equivalent elements of the other set or sets (mathematics)

isomorphˈous adjective

isomorphous mixture noun

A mixed crystal or solid solution in which isomorphous substances are crystallized together by vicarious substitution