Rodney W. Nichols, who held high-level scientific and academic positions at the Pentagon, Rockefeller University and the New York Academy of Sciences and who promoted the connection between science and diplomacy, died Aug. 30 at a hospice in New York City. He was 80.

The cause was complications related to lymphoma, said his son, Christopher McKnight Nichols.

Mr. Nichols, a Harvard-trained physicist, began his career at Melpar, a Washington-area defense contractor and a subsidiary of Westinghouse. He then spent several years at the Defense Department, working in research and development.

In 1970, Mr. Nichols moved to New York, where he spent 20 years as a top administrator at Rockefeller University, a graduate school of biomedical research that has one of the world’s highest concentrations of Nobel laureates. In 1977, he helped organize a visit by Rockefeller University scholars to China, spurring a lifelong interest in scientific and cultural exchange.

After two years at the Carnegie Commission on Science, Technology, and Government, where he helped write a study on the importance of science and technology in international affairs, Mr. Nichols became president and chief executive of the New York Academy of Sciences in 1992. The venerable organization, which was founded in 1817 and counted Thomas Jefferson, Charles Darwin and Albert Einstein among its members, faced financial struggles and declining membership during Mr. Nichols’s nine-year tenure.

“This is a 19th-century organization, and it’s organized in a 19th-century way,” he told the New York Times in 2001.

He closed the academy’s prestigious but money-losing magazine, The Sciences, and proposed selling its stately headquarters on New York’s Upper East Side. The moves prompted widespread dissension among the academy’s members.

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“Some people think I’m an assassin,” Mr. Nichols admitted to the Times. “I don’t feel good about the whole situation. I feel good about the decision. I don’t feel good in human terms.”

He resigned at the end of 2001, saying his continued presence had become “a distraction.” He then became an independent consultant, writer and teacher, and he helped develop a course at Rockefeller University exploring the links between science and diplomacy.

Rodney Wayson Nichols was born Sept. 15, 1937, in Evanston, Ill. He moved as a child to the Washington area, where his father was an economist with the Commerce Department.

At Washington-Lee High School in Arlington, Va., he was a state champion in tennis. He received a bachelor’s degree in physics from Harvard University in 1959.

Mr. Nichols was an adviser to the White House Office of Science and Technology Policy, the Defense and State departments, National Institutes of Health, and other governmental and scientific groups. He was a board member of CRDF Global, which seeks to promote scientific and diplomatic connection with Middle Eastern countries, and was a fellow of the American Association for the Advancement of ­Science.

His first marriage, to the former Carolyn McKnight, ended in divorce. His second wife, the former Nancy Stephenson, died in 2002. Survivors include his wife of seven years, Karen Landau of New York; a son from his first marriage, Christopher McKnight Nichols of Corvallis, Ore.; a stepdaughter from his second marriage, Courtney Chilov of New York; a stepdaughter from his third marriage, Lily Landau of New York; and a brother. A stepdaughter from his second marriage, Lindsey Stephenson Brown, died in 2006.