  We briefly report on calculated addition spectra for electrons in a circular
quantum dot with perpendicular magnetic field. We compare our current density
functional theory calculations with recent experiments by Tarucha et al. [PRL
77, 3613 (1996)]. We find a very good qualitative agreement of the structures
and find an additional effect caused by Hund's first rule in magnetic field,
which gives rise to new substructures not discussed in the paper by Tarucha.
