ELIMINATION OF LOCAL-SPIN-DENSITY-APPROXIMATION ERRORS FROM ELECTRONIC-STRUCTURE CALCULATIONS OF GD

All previous electronic-structure calculations of Gd have obtained a density of states N(E(F)) much larger than the experimental value. By comparing Hartree-Fock with local-spin-density-approximation (LSDA) atomic calculations we previously concluded that the minority-spin 4f resonance just above E(F) in the metal, which is responsible for the enhanced N(E(F)), is an artifact of the LSDA. We present here a calculation for the Gd crystal in which the conduction electrons experience a Hartree-Fock potential due to the core electrons and a LSDA potential due to themselves. The resonance is gone, N(E(F)) is less than the experimental value (many-body effects will increase it), and the lattice constants are in near-perfect agreement with experiment.