THE BAND MODEL FOR THE GROUND-STATE PROPERTIES OF GADOLINIUM METAL

The authors describe the electronic structure of Gd within the local spin density functional approximation treating the 4f electrons on equal footing with the s, p, d valence electrons. This band model is solved with the LMTO-ASA method, which includes the spin-orbit coupling and spin polarisation. The model gives a reasonable description of electronic structure properties such as the spin magnetic moment and the Fermi surface. Total energy calculations indicate that the experimentally observed HCP structure is favoured over both FCC and DHCP structures. Freezing the 5p semi-core states overestimates the lattice constant by 3.9%, while relaxing them as band states gives an underestimation of 3.4%, indicating a strong sensitivity to the treatment of these states.