This collection includes correspondence, publications, and research materials from the life and career of University of Oklahoma physics professor J. Rud Nielsen. The papers focus on his research files, his publications, and collected works by other authors. The research files include his work on early volumes of Niels Bohrs Collected Works; his research on molecular structure using Raman spectroscopy;reports of grant and contract projects for the Office of Naval Research, National Science Foundation, and the U.S. Atomic Energy Commission; and materials for physics courses taught at OU. Other materials document OU Physics Department events such as Niels Bohrs visits to the Norman campus for public lectures. The collection also includes 1,041 glass slides depicting research results and physics principles; and printing blocks of graphics for articles in the Journal of the Optical Society of America and the Journal of Chemical Physics.