After early work with Lauritsen on excited states in 6Li, Nilsson became interested in evidence that heavy nuclei could be deformed into ellipsoidal rather than spherical shapes.
His research, in collaboration with Bohr and Mottelson, led to the so-called Nilsson model and a 1955 doctoral thesis, "On some properties of nuclear states.
Nilsson and Mottelson embarked on a comprehensive program of comparing nuclear properties with the predictions of the deformed shell model.
Sven Gösta Nilsson was involved in the work of CERN's Theoretical Study Division when the group was located in Copenhagen.
[3] Starting in 1963, he was a professor of mathematical physics at the two-year-old Lund University of Technology, helping to build its research programs.