A new nickel germanide, NiGe2, was synthesized under high pressure and temp
erature condition and the crystal structure was solved by the Rietveld anal
ysis of the powder X-ray diffraction data. Single phase NiGe2 was obtained
from the stoichiometric mixture of elemental components by the reaction at
5.5 GPa and 700 degrees C. The compound crystallizes into orthorhombic stru
cture with the space group Cmca, isostructural with CoGe2. Lattice paramete
rs were determined to be a=10.830(5) Angstrom, b=5.763(3) Angstrom, c=5.762
(3) Angstrom. The structure contains isolated Ni-Ni bonds dong the a-axis.
The compound is a metallic conductor with a temperature independent suscept
ibility. (C) 2000 Elsevier Science S.A. All rights reserved.