[en] The Raman and Ir spectra of NH2NHCSSCH3, Ni(NH2N=CSSCH3)2, its 58Ni, 62Ni and deutero analogues were investigated from 4000 to 33 cm-1. Empirical band assignments were made on the basis of metal-isotope shift and N-deuteration data. The results indicate that two chelating ligands coordinate to the central Ni atom through both S and N atoms, and that the Ni complex is of trans square-planar structure. (author)