We study, using first principles calculations, the electronic and structura
l properties of an isolated vacancy and self-interstitial defects in german
ium. For the vacancy we analyze the lattice relaxations for the charge stat
es (+ +), (+), and (0), and show that the atomic displacements, albeit smal
l, are not completely negligible for the second-nearest-neighbor atoms to t
he vacancy site. Moreover, we show that the relaxations decay slowly along
the zigzags that go through the vacancy site. For the self-interstitial we
present an analysis of the charge density, which supports the description o
f this defect as a four-atoms ring strongly attached to the lattice, which
we have named a kite-defect (C) 2001 Elsevier Science B.V. All rights reser
ved.