[2] During World War II, he was part of a team of German scientists studying nuclear power and was advisor to the production of heavy water in a Norwegian plant (see Operation Gunnerside).
After the war, he collaborated on the shell model of the atomic nucleus with future (1963) Nobel Prize winner Hans Jensen.
He did research in the field of cosmochemistry, investigating the abundance of certain elements in meteorites with Harold Urey (Nobel Prize in Chemistry, 1934) at the University of Chicago.
On basis of radiocarbon analyses of annual growth-rings of trees he contributed to The mineral suessite, a Fe, Ni-silicide in Enstatit-Chondrites, is named after him.
The two names have been posthumously linked as well: both men's personal papers are housed in Geisel Library at the University of California, San Diego.