Near‐ultraviolet absorption spectra for the I(1/2)u→II(1/2)gtransition have been calculated for Ne+2, Ar+2, Kr+2, and Xe+2usingabinitioconfiguration interaction methods. The spectra are all similar except that the position of maximum absorption shifts to longer wavelength for the heavier rare gases. The absorption cross sections are tabulated at the wavelengths of the KrF, XeBr, XeCl, and XeF lasers.