Berkeley - Walter D. Knight, professor emeritus of physics at the University of California, Berkeley, and an innovative researcher in the field of nuclear magnetic resonance, died Wednesday, June 28, at his summer home in Marlborough, N. H. The cause of death was heart disease complicated by end-stage Alzheimer's disease. He was 80.

Knight, who retired in 1990, was a member of the National Academy of Sciences and a former dean of the College of Letters & Science at UC Berkeley. He came to Berkeley in 1950 as a young scientist at the forefront of the then-new field of nuclear magnetic resonance, a technique for studying details of the atomic nucleus. Nuclear magnetic resonance (NMR) has since been applied to many fields, including magnetic resonance imaging in medicine.

In the words of his colleagues, Knight was "a consummate experimentalist" who concentrated on the study of the physical properties of metals. He discovered a new NMR phenomenon - what his colleagues dubbed the "Knight shift" - which was a significant development in the understanding of the electronic properties of metals. He pioneered the use of electric quadrupole resonance as well as magnetic resonance as sensitive probes in studying structural and other changes in metal crystals. His research also played a crucial and unique role in understanding the electronic properties of metallic alloys and superconductors.

Later in his career, he initiated ground-breaking work on the physics of small metal clusters, now referred to as nanoclusters. He discovered their electronic shell structure and traced the development of metallic properties as clusters increase in size. This field has blossomed in the past 20 years, attracting chemists and engineers as well as atomic and solid state physicists.

He played a major role in building the field of solid state physics at UC Berkeley, yet he relished teaching introductory physics courses, in particular those for pre-medical and liberal arts students. His abiding interest and concern for students led him to get involved in campus administration.

"He was a very caring, conscientious person who was extremely supportive of his students and of the university," said colleague Alan M. Portis, professor emeritus of physics at UC Berkeley.

Amid turbulent times in the 1960s, he assumed the position of dean of the College of Letters & Science, winning the praise of many for his handling of difficult issues involving students and faculty alike. He was once forced to barricade himself and his staff in Moses Hall overnight to protect confidential faculty and student files from rampaging students until police could rescue them.

Born in New York City on Oct. 14, 1919, he graduated from Middlebury College in Vermont in 1941 and obtained his MA in 1943 and his PhD in 1950 from Duke University. His education was interrupted by two years as a radar officer in the U.S. Navy during World War II, where he received a grounding in electronics that subsequently proved useful in his experiments. From 1946 until he received his PhD in 1950, he taught on the faculty at Trinity College, Hartford, Conn. He joined the UC Berkeley physics faculty in 1950 and became a full professor in 1961.

Knight served as assistant and then associate dean of the College of Letters & Science from 1959 until 1967, when he was appointed dean. The college is the largest at UC Berkeley, and he soon realized it was too large to be overseen by one person. Before he returned to teaching in 1972, he split the unwieldy job among four new deans - one each for the humanities and the physical, biological and social sciences - and relinquished his job to a new position of provost.

He was a fellow of the American Physical Society and of the American Association for the Advancement of Science, and a member of the American Academy of Arts and Sciences. He held two honorary degrees, from Middlebury College and the Ecole Polytechnique Federale de Lausanne.

Upon his retirement, he received the campus's highest honor, the Berkeley Citation.

Knight is survived by his wife of 28 years, Sara Pattershall Knight, of Berkeley; their son Nathaniel Knight of Berkeley; two children from a previous marriage, Margaret Knight of Washington, D.C., and Jonathan Knight of El Cerrito, Calif.; a stepson, Eric Blanpied, of Berkeley; and a sister, Paula Knight Jeffries, of Washington, D.C. and Marlborough, N.H. He also leaves five grandchildren.

Burial will be in New Hampshire on July 17. A memorial service is planned for the UC Berkeley campus sometime in September. His family requests that donations in his memory be made to the Department of Physics, MC 7300, University of California, Berkeley CA 94720-7300.