  The electronic structure and equilibrium geometry of La2/3Sr1/3MnO3 are
studied theoretically by means of density functional calculations. The doping
is treated by introducing holes and a compensating jellium background. The
results for the local density approximation (LDA) agree with previous LDA
calculations, with an equilibrium volume 5.3% too small and with both majority
and minority spin states present at the Fermi level for the relaxed system. The
generalised gradient approximation (GGA) offers a qualitatively improved
description of the system, with a more realistic volume, and a half-metallic
behaviour for the relaxed structure, which enables studies needing theoretical
relaxation.The ideal MnO2-terminated (001) surface is then described with
explicit doping.
