SCF-Xa-SW calcns. are carried out on 10 LnF3 compounds with Ln being Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. Both of the nonrelativistic and relativistic schemes have been tried. Energy sequences, contour maps, binding energies, atomic populations, and ionization potentials are given in order to explore the chem. bonding with emphasis on the behavior of the f-orbitals and the role of relativistic effects.

Key words: COMPUTATIONAL METHOD, LANTHANON, FLUORIDE, NEODYMIUM COMPOUNDS, EUROPIUM COMPOUNDS, CHEMICAL BONDS, CHROMIUM COMPOUNDS, ENERGY LEVELS, IONIZATION ENERGY, MOLECULAR ORBITAL THEORY