Spectral Relations Between Certain Iso-Electronic Systems and Sequences, Part III; Ti I, V II, Cr III, Mn IV, and Fe V

Spectral relations between the iso-electronic systems, Ti I, V II, Cr III, Mn IV, and Fe V.---The removal of, one valence electron from neutral vanadium, two valence electrons from neutral chromium, three valence electrons from neutral manganese, and four valence electrons from neutral iron forms with neutral titanium the five isoelectronic systems Ti I, V II, Cr III, Mn IV, and Fe V.The irregular doublet law.---The irregular doublet law, wherever applicable, proves to be a powerful method of attack in attempting to analyze the spectra arising from ionized atoms. In this report for the electron transition 3d³4p to 3d³4s about forty lines, and for the electron transition 3d³4d to 3d³4p about twelve lines, have been traced through the first three elements Ti I, V II and Cr III. In the first electron transition the multiplet ⁵F^'-⁵G^' has been traced as far as Fe V.Term separations, The Land\'e interval rule, and Hund's rule.---The systematic increase in term separations is given for the ⁵F^' and ⁵G^' terms arising from the electron configurations 3d³4s and 3d³4p respectively. For these same terms the Land\'e interval rule is found to be in general agreement with observed separations. Hund's rule for relative term positions is followed for the terms thus far identified.Energy levels and the Moseley law.---A new type of energy level Moseley diagram for Ti I to Fe V is compared with a similar diagram for the three sequences starting respectively with Sc I, Ca I, and K I. These four diagrams together with a similar diagram for V I, V II, V III, V IV, and V V are found to be almost identical. The constancy in the values of Δλ between the diagonal lines of certain multiplets is traced through the first five elements of each of the four iso-electronic sequences starting with Ti I, Ca I, Sc I and K I.