First-principle electronic structure of rare earth arsenides

The electronic properties of rare-earth arsenides have been calculated from first principles. Inthe calculations we have treated the rare-earth f electrons both as core-like and as valence-like electrons.We consider the changes in the energy bands and in the density of states near the Fermi level which arefound to be relevant, except for the case of LuAs, and discuss this in relation with the role played fromthe rare-earth 5d derived states. Moreover we show that the rare-earth 5d related bands are particularlysensitive to the variation of the lattice constant; change in the lattice constant of less than 1% leadsto a different behaviour with respect to the crossing of the rare-earth 5d derived bands and the As 4pderived bands along the-direction. This point is discussed in connection with the possibility of having asemimetal-semiconductor transition in the rare-earth arsenides.