In an on-going effort to design and synthesize chemical substances that can safely and effectively remove plutonium and other radioactive materials from the human body or from the environment, scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have made an important advance. Using the exceptionally bright and intense x-ray beams of Berkeley Lab’s Advanced Light Source (ALS), they have determined the crystal structure of a molecular complex that has shown promise as a sequestering agent for plutonium and other members of the actinide family of elements.