The emission spectrum of doubly ionized nitrogen, N III, has been studied at high resolution in the extreme ultraviolet, from 150 to 500 Å. Eighty seven new terms are reported, belonging to singly, doubly, and triply excited electron configurations; the data include two hundred and fifteen new spectral lines. Many of the lines observed are due to transitions from autoionizing levels and some exhibit broad and asymmetrical profiles as predicted by the theory. An example of forced autoionization is noted.
Donald J. Michels, "Extreme-ultraviolet spectrum of N III," J. Opt. Soc. Am. 64, 1164-1174 (1974)