  The ThCr2Si2-type arsenide-selenide phase KFe2AsSe is proposed as a parent
system for a new "intermediate" group of Fe-based superconducting materials
bridging the known families of Fe-pnictides (such as BaFe2As2) and
Fe-chalcogenides (such as KxFe2-ySe2) superconductors. The characterization of
the proposed charge-balanced phase by means of FLAPW-GGA approach covers the
crystal structure, As/Se atomic ordering, stability, electronic bands, Fermi
surface, and density of electronic states.
