Rare-Earth and Transuranic Elements

Abstract

The possible existence of a second rare-earth-like group of elements beginning with uranium and extending to the transuranic elements, is discussed by a calculation of the atomic eigen-functions of the $4f$ and $5f$ electrons. Energy and spatial extension of the $4f$ eigenfunctions drop suddenly at the beginning of the rare-earth group; the binding energy is calculated to be 0.95 ev in lanthanum, $Z=57\mathrm{}$, and 5 ev in neodymium, $Z=60\mathrm{}$. The $5f$ eigenfunctions undergo the same type of change around $Z=92\mathrm{}$. The binding energies were calculated to be 1.35 ev for $Z=86\mathrm{}$, 8.5 ev for $Z=91\mathrm{}$ and 14 ev for $Z=93\mathrm{}$.