REFINEMENT IN CRYSTAL-STRUCTURE OF MOSI2

The crystal structure of MoSi2 was investigated using a synchrotron X- ray powder diffraction method. From the Rietveld analysis it was shown that MoSi2 had a tetragonal structure of the space group I4/mmm and t he lattice parameters were a = 032064(2) nm and c = 0.78478(8)nm. The position of Si atoms in the 4e site was determined to be (0, 0, 0.3353 ). There was a small shift in the z position, as compared to the previ ously reported value, 0.3333. The electronic structure of MoSi2 was ca lculated by the DV-X alpha molecular orbital method employing the refi ned structural parameters, and this showed that there was a strong cov alent bond between Si atoms aligned along the c axis in MoSi2. (C) 199 8 Published by Elsevier Science Limited. All rights reserved.