We report on the ESR of the rare-earth ions Nd +, Gd +, Er +, and Yb + on powdered samples of various intermetallic compounds of AB2 cubic structure where 8 is a transition-metal ion belonging to the group VIII of the Periodic Table, and A is a nonmagnetic ion (La, Ce, 'Y). The resonance of the Nd + in these compounds originates within a 16 crystal-field ground level and exhibits resolved hyperfine satellites for the ' Nd and ' Nd isotopes. The Gd + spectra show a single isotropic line. Using our data for Gd + and Nd + together with results previously published for the AB2 cubic compounds, we were able to show a correlation between the observed g shifts and the position of the 8 ion in the Periodic Table. This variation is explained qualitatively using a simple multiband model, as well as band-structure arguments. The hyperfine constants for the Nd and ' 5Nd isotopes were found smaller in magnitude with respect to the values in insulators; this effect is attributed to s-electron self-polarization due to the Nd localized-moments-electron exchange coupling. The ESR linewidths of LaIr2'. Nd and LaRh2'. Nd exhibit an exponential thermal dependence at high temperatures which is attributed to the presence of a I 8 excited level at 5 =-90+ 20 K.

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