Molecules that have the same structural formula but different spatial arrangements of dissimilar groups (of atoms) bonded to a common atom (in the molecule). Many of the physical and chemical properties of stereoisomers are the same, but there are differences in the crystal structures, in the direction in which they rotate polarized light (which has been passed through a solution of the stereoisomer), and in their use in an enzyme-catalyzed (biological) reaction.
Isomers having the same atoms but whose structure has one or two slight differences in the position of these atoms.
Compounds having the same molecular formula but different three-dimensional arrangements of their atoms. The atomic structures of stereoisomers are mirror images of each other.