Calculation of Chemical Shifts of X-Ray-Emission Spectra of Niobium in Niobium(V) Oxides Relative to Metal

Chemical shiftsof the Kα1 and Kβ1 lines of X-ray-emission spectra of niobiumin oxides (Nb2O5)n, n = 1–4, relative to metal Nb have been calculated. Stoichiometric clusters (Nb2O5)n the electronic structure of which was calculated using accurate relativistic pseudopotentialsand two-component version of the density functional theory are considered as prototypes for modeling different crystal forms of niobium(V) oxide. The chemical shiftswere calculated using the method based on using the property of approximate proportionalityof valence spinorsin the core region of the heavy atom [11]. Corrections to values of chemical shiftshave been determined with allowance for deviations from the abovementioned proportionality. Rapid convergence of results with respect to the size of the niobium oxidecluster has been demonstrated.