CHEMICAL-SHIFT OF X-RAY K-ABSORPTION EDGE OF NI IN SOME OF ITS COMPOUNDS AND ITS CORRELATION WITH PARTIAL CHARGE

X-ray absorption Ni K-edge spectra are recorded for the following syst ems: Ni metal, Ni(NO3)(2) . 6H(2)O, Ni-3(PO4)(2) . 6H(2)O, NiSO4 . 6H( 2)O, NiCO3, NiO and La2NiO4 using a Cauchois-type bent crystal spectro graph. The chemical shift of these systems is correlated with the part ial charge determined using Sanderson's method. On the basis of regres sion analysis a relation Delta E = A(0) + A(1)q + A(2)q(2) + A(3)q(3) + A(4)q(4) between the chemical shift, Delta E, and the partial charge , q, has been suggested. The discrepancy in the shift of NiO and La2Ni O4 has also been discussed.