George Hsing Kwei, known for his seminal research in chemical physics, particularly on molecular collision dynamics and neutron diffraction, as well as administrative service at Los Alamos National Laboratory, died on 10 June 2005 in San Francisco from a hemorrhagic stroke.
George was born in Hunan province in China on 17 November 1938. In his childhood George lived in Switzerland, where during World War II his father, General Kwei Yun-Ching, headed a diplomatic mission. After the war, his family returned to China, but moved to Taiwan in 1949 when the Nationalist government fell. He came to the U.S. at the age of 12, studied at the Stockbridge School, and at 16 entered Harvard University. Already as an undergraduate, George did significant work in microwave spectroscopy, working with R. F. Curl, Jr. in the laboratory of E. Bright Wilson, Jr. In 1959, George graduated with honors in chemistry and physics.
He then pursued graduate studies at the University of California at Berkeley. He was the first student to join his mentor, Dudley Herschbach, in undertaking experiments using molecular beams to resolve chemical reaction dynamics under single-collision conditions. George had a key role in pioneering studies of reactions of alkali atoms with halogen compounds. Termed the “early alkali age” of molecular beam chemistry, that work presaged the development of a major field. Characteristically, George asked to construct his own state-of-the-art apparatus, which he named Gloria, in honor of his future wife. Likewise, he produced a much more extensive thesis than required; it long served as a manual for his successors. He received his Ph.D. in 1967 and joined the chemistry faculty at the State University of New York, Stony Brook. There he conducted experiments and classical trajectory calculations dealing with long-lived collision intermediates and also made a unique study of the reaction of hydrogen atoms with tritium molecules.
In 1974 George became a research scientist at Los Alamos National Laboratory. He conducted several experiments on collisional energy transfer, especially exchange of electronic excitation, and laser-induced photodissociation and ionization. He also elucidated the dynamics of the reaction of nitric oxide with ozone, which has a major role in stratospheric chemistry. For this work, he again constructed a major molecular beam apparatus. Increasingly asked to take on administrative responsibilities, in 1982 he became Deputy Associate Director for Chemistry, Earth, and Life Sciences. In that position, he helped launch several new initiatives, including entry into resonance ionization mass spectroscopy, synchrotron beam line instrumentation, and instituting a molecular biology program which eventually contributed to the National Human Genome Project.
Despite his effectiveness in high-level administration, George returned to research in 1988. Remarkably, he undertook work in a field wholly new to him, structural studies of materials by means of neutron and x-ray diffraction. Over the next 14 years, he published more than 100 papers, many treating mixed valency solids, including high temperature superconductors, others demonstrating structural instabilities near phase transitions, ordering on nanometer length scales, and intercalation into fullerene interstices. An important aspect, exemplified in much of his work, was its focus on “local” structure. The customary crystallographic refinement procedure for Bragg scattering from a powder diffraction pattern provides structural information that is averaged over several hundred angstroms or more. This extensive averaging is imposed by the presumption of strict periodicity. George advocated and demonstrated the advantages of evaluating pair-distribution functions from the same powder diffraction data. That method, ordinarily used for gases or liquids, reveals local structural variations and distortions from crystal symmetry. It proved particularly fruitful in analysis of metallic alloys, order-disorder transitions, superconductors, and proteins.
In 1994, George moved to Lawrence Livermore National Laboratory, but continued to pursue projects at several neutron source facilities in collaboration with researchers from institutions from across the US and Japan. He took leave in 1997 to return to Los Alamos, where responsibilities included a two-year assignment as a Special Assistant in the Director’s Office. He returned to Livermore in 2000, and was awarded the Edward Teller Fellowship in recognition of his scientific accomplishments. Beset by ill health, he retired in 2002. Although unable to complete the book he intended to write on science policy as his Teller Fellowship project, he much enjoyed writing letters to newspapers on political issues and seeing a number of them published.
George lived his life with passion and pleasure. To his scientific work, he brought joyful enthusiasm as well as intellectual acuity and virtuoso craftsmanship in constructing apparatus and doing experiments. His willingness to ask “dumb” questions enabled him to bring fresh perspectives to any new endeavor. In those privileged to work with him, he fostered a congenial team spirit. He was especially sensitive to the professional development of his postdocs and younger colleagues, and he took great pride in their later achievements. These attributes were enhanced by George’s warm good humor and ample supply of apt stories as well as his high standards and astute judgment. He was generous in acknowledging the contributions of his colleagues. These qualities likewise served him well in his administrative tasks.
Beyond science, he was intensely devoted to his family and many friends. With them, he shared with gusto his love of music, art, fine wine and food. Even in his graduate student days at Berkeley, he led his fellow researchers on many trips to savor restaurants in San Francisco; George always knew, week-by-week, where the best chefs were performing. At Los Alamos, his hobby activities focused in succession on racing bicycles, fine violins and bows, and the construction of an elegant harpsichord. George was directly responsible for Yo Yo Ma’s first New Mexico appearance, at a performance for the Los Alamos Concert Association. He seemed magically to acquire encyclopedic knowledge of any area that gained his interest. Over the years, he assembled more and more splendid high fidelity equipment. Ultimately, his gear included a pair of big bass horns that are more than a meter in diameter. He delighted in seating visitors between those massive horns, adjusting ears by a few millimeters to achieve optimal results.
George leaves behind his wife, Gloria; their daughter Erica and son Lawrence, daughter-in-law Denise, and three grandchildren. In cherishing his memory, they are joined by his host of friends and colleagues, who he gladly made his wider family. Thinking of him always brings forth a vision of his smile. Earnestly charming, often playful, his smile radiated happiness in sharing with others his wholehearted zest
Dudley R. Herschbach
James L. Kinsey