Calculation of electronic parameters and vacancy distribution in cubic niobium carbide

Evaluations of electron energetic parameters of cubic niobium carbide are carried out according to the known thermodynamic data on partial heats of evaporation of niobium and carbon atoms. The parameters are used to calculate temperature dependence of vacancy distribution in niobium carbides of different compositions in the limits of its cubic phase. The calculation results point to the existence of the short-range order in the vacancy distribution which promotes to the ordering of the long-range order in NbCsub(0.75)