Retired Army Maj. Gen. David B. Parker, 63, a Corps of Engineers officer and authority on atomic weapons, died Sunday at Walter Reed Hospital. He had a heart ailment.

His last assignment was that of commander of the Army Support Command, Europe, in Heidelerg, Germany, where he retired in 1967. Since then he had lived in McLean.

During World War II, Gen. Parker served at Gen. Douglas MacArthur's headquarters in Australia and then was an engineer battalion commander in six major campaigns in the Pacific. He was awarded the Bronze Star.

In 1946, he became chief of the military operations division of the Manhattan Project, which developed the atomic bomb. Later, he wrote a number of articles on the military effect of atomic weapons.

Gen. Parker was assistant to the deputy assistant chief of staff for atomic energy of the Army General Staff here from 1948 to 1952, when he transferred to Supreme Headquarters Allied Powers, Europe (SHAPE) as Army atomic planner in the office of the air deputy. Later he was secretary of the SHAPE staff.

Gen. Parker served here as assistant Army chief of transportation for research and development and as transportation officer for the U.S. Army in Europe.

A native of Denver, he grew up in Washington, where he graduated from Western High School. Like his father and two older brothers, he graduated from the U.S. Military Academy at West Point. He earned a master's degree from the Massachusetts Institute of Technology.

After his retirement from military service, Gen. Parker was a consultant for several years with the Research Analysis Corporation here.

He is survived by his wife, the former Metta Rosencrantz, and a son, Henrik Davidson Parker, both of McLean; a daughter, Viveca Davisdotter Parker, of London, England, and two brothers, retired Army Col. Edward M., of Washington, and retired Army Col. John R., of Lexington, Ky.

The family suggests that expressions of sympathy be in the form of contributions to the Woodburn Center for Community Mental Health in Annandale.