Robert D. Shannon is a distinguished chemist renowned for his fundamental contributions to inorganic chemistry and crystallography. Born in Highland Park, Michigan in 1935, he earned his B.S. and M.S. from the University of Illinois before completing his Ph.D. at the University of California, Berkeley in 1964. He spent the majority of his career as a research chemist at DuPont de Nemours, Inc., where he conducted groundbreaking work that established him as a leading figure in his field. Following his retirement from industry, he maintained an active research presence through affiliations with the University of Colorado Boulder, where he continued to influence the scientific community through his scholarly contributions.
Dr. Shannon's most significant contribution is his comprehensive tabulation of ionic radii, first published in 1976, which has become an indispensable reference for researchers worldwide. This seminal work was recognized in a 2014 Nature paper as the 22nd most cited paper in all of science and has accumulated over 77,000 citations across his approximately 164 publications. His rigorous methodology for determining ionic radii provided a standardized framework that resolved longstanding inconsistencies in crystal chemistry measurements. The extraordinary impact of this work earned it recognition as the highest formally-cited database of all time, fundamentally transforming how scientists understand and predict the behavior of ionic compounds in materials science, geology, and chemistry.
The profound influence of Dr. Shannon's work was formally recognized through the naming of the mineral bobshannonite in his honor, acknowledging his major contributions to crystal chemistry and mineralogy. His research on dielectric properties of minerals and noble-metal oxides has provided critical insights for materials scientists developing advanced electronic components and catalysts. With numerous patents to his name covering glass compositions, zeolite catalysts, and chemical compounds, his work has bridged fundamental science with practical applications. Dr. Shannon's legacy continues to shape multiple scientific disciplines, as his ionic radii tables remain a cornerstone reference for researchers across the globe, cementing his place among the most influential chemists of the modern era.
