The electronic structures of rare-earth elements in the HCP structure, and
Europium in the BCC structure, are calculated by use of density-functional
theory, DFT. Simulation of X-ray photoemission spectroscopy (XPS) and
bremsstrahlung isochromatic spectroscopy (BIS) are made within DFT by imposing
that f-electrons are excited by a large photon energy, either by removing from
the occupied states in XPS, or by adding to the unoccupied f-states in BIS. The
results show sizable differences in the apparent position of the f-states
compared to the f-band energy of the ground states. This result is
fundamentally different from calculations assuming strong on-site correlation
since all calculations are based on DFT. Spin-orbit coupling and multiplet
splittings are not included. The present simulation accounts for almost half of
the difference between the f-level positions in the DFT ground states and the
observed f-level positions. The electronic specific heat at low T is compatible
with the DFT ground state, where f-electrons often reside at the Fermi level.Comment: 8 pages, 6 figures, 2 table
