The Nobel Prize in Chemistry 1985 was awarded jointly to Herbert A. Hauptman and Jerome Karle "for their outstanding achievements in the development of direct methods for the determination of crystal structures".
 

Through Hauptman's and Karle's fundamental achievements, the methods have been developed into practical instruments for determining the structure of molecules within both inorganic and organic chemistry - not least within the chemistry of natural products. The determination of structure involves generating a three-dimensional picture of the positions of the atoms. The picture maps the electron density within the crystal the density is greatest at the centre of the atoms. It can never be less than zero anywhere, and this is the fact upon which the Hauptman-Karle method is based. In order to understand the nature of chemical bonds, the function of molecules in biological contexts and the mechanism and dynamics of reactions, knowledge of the exact molecular structure is absolutely necessary.