Crystal and electronic structure of Ni3Bi2S2 (parkerite)

The crystal structure of parkerite, Ni3Bi2S2, was studied by single-crystal X-ray diffraction analysis and refined. The single crystal was prepared by the method of chemical transport reactions. The electronic structure of Ni 3Bi2S2 was calculated by the extended Huckel and DFT-LMTO-ASA methods. Subs tantial delocalization of electrons in the vicinity of the Fermi level and the presence of the strong Ni-S and Ni-Bi bonds were revealed. The Ni-Ni bo nds are weak, which is in agreement with the X-ray diffraction data.