Personal, scientific, and other correspondence, manuscripts, reprints, photographs, doctoral thesis, data books, samples of specimens, and lecture research notebooks. The bulk of the collection is post-1947 correspondence. Includes materials on x-ray diffraction and crystallography, and academic freedom, as well as Fankuchen's early research in molecular biology. Correspondents include: John Desmond Bernal, George Lindenberg Clark, Norman Fordyce McKerron Henry, Richard Fiske Jarrell, Raymond Pepinsky, Aaron Sidney Posner, Dorothy Wrinch, the American Crystallographic Association, the American Society for X-Ray and Electron Diffraction, the International Union of Crystallography, the National Bureau of Standards, National Research Council, National Science Foundation, the U.S. National Committee on Crystallography for the International Union of Crystallography, and representatives of various academic institutions, journals, publishing companies, technical and humanitarian societies, industry, and government agencies.