Not to be confused with Isotopologue.
Isotopomers or isotopic isomers are isomers with isotopic atoms, having the same number of each isotopic atom but differing in their positions. It can be either constitutional isomers or stereoisomers. For example, CH3CHDCH3 and CH3CH2CH2D are a pair of constitutional isotopomers. (R)- and (S)-CH3CHDOH or (Z)- and (E)-CH3CH=CHD are examples of isotopic stereoisomers. 
An isotopomer should not be confused with an isotopologue.
1 13C NMR