Observations of the spark spectrum of Ge from 4741 A to 7145 A have made possible the improvement of certain of the term values of Ge II. By combining their interferometric wavelength measurements with unpublished data of C. W. Gartlein the authors were able to determine the fine structure of four 4s2nƒ2F° terms of Ge II. All the terms for n=4, 5, 6, and 7 are inverted and the splittings range from 0.47 to 0.75 cm-1. Values were obtained for the unresolved 4s2ng2G terms for n=6 and 7.
K. L. ANDREW and K. W. MEISSNER, "Contribution to the First Spark Spectrum of Germanium (Ge II)," J. Opt. Soc. Am. 49, 1086-1087 (1959)