The Tables of energy levels are presented in a way similar to the "Atomic Energy levels the Rare Earth Elements", and incorporate additionnal data: isotope shifts and hyperfine structures. For each spectrum, they are separated in two lists of odd and even levels, the parity of the ground level being given first. The content of the successive columns is:
First column: the reference of the discovery, in which the energy of the level was reported for the first time.
Second column: the reference of the identification, in which the present identification was reported for the first time. The filling of these first two columns was tedious, time consuming and, in some cases difficult to ascertain. It is hoped that the readers will appreciate this help in their bibliographic research. The authors apologize for possible errors.
Third column: the configuration which may include, in addition to the electrons, the Russell-Saunders term, or J quantum number of parent sub-configurations. For configurations with more than two equivalent electrons, the terms with same S and L values are discriminated with an index, the same as used by C.W. Nielson and G.F. Koster (68).
Fourth column: The Russel-Saunders term, or (jl, j2) multiplet, may be the result of a theoretical interpretation following the Slater-Condon method if the column composition is filled; if not, this label has been given on semi-empirical grounds (intensity of the transitions, regularity of the electron jumps versus atomic number {an exemple being given in fig. 3}, hyperfine structure, g-factor or analogy with the lanthanides). If the first LS component of the eigenfunction is less than 50 % of the total, term designations are generally skipped.
Fifth column: the total angular momentum J
Sixth column: the energy is given as usual in cm-1 , from the most accurate data available (indicated in the headings) and it may be different from the values reported in the references of the first two columns. For odd-Z elements, the energy is the center of gravity of the hyperfine structure components for the indicated isotope.
After the sixth column, the data described below are missing in a number of spectra.
- The Landé factor g is derived from Zeeman effect studies referenced in the headings or in the introduction.
- The hyperfine stuctures have been included in the present Tables because they characterize the levels of odd-Z elements in absence of measurable Zeeman patterns. The compiled data are the total width of the level W = EF> - EF< with F> = 1 + J and F< = 1 - J, the structure of the ground level (or another level as specified in the introduction) being taken as an arbitrary zero reference. When the magnetic dipole hfs constant A and electric quadrupole constant B have been derived from a detailed analysis of the whole hfs patterns, they are reported in addition (or instead of) W. The usual unit for all these data is 10-3 cm-1.
- The isotope shift DT of the level is given in 10-3 cm-1 for a couple of isotopes indicated in the headings, an arbitrary zero value for one level (generally the ground level) being taken as a reference.
- The first two components of the eigenfunction are given in percents (square of the amplitude with no sign indicated). In a few cases, these data are replaced by the first component in two different couplings.