Relativistic augmented-plane-wave calculations for Gd, Dy, Er, and Lu are reported. Energy bands, histograms of the density of states, and Fermi-surface cross sections are given. The Fermi surfaces of Dy, Er, and Lu are found to be quite similar to the one given earlier for yttrium. The Fermi surface of Gd is found to differ from the others by the absence of a "webbing" feature. Nesting between the sheets of the webbing is correlated with the occurrence of periodic moment arrangements in Dy, Er, and alloys of Y and of Lu with certain magnetic rare earths.

• Received 26 October 1967

DOI:https://doi.org/10.1103/PhysRev.168.672