A study was made of the effect of vacancies upon the structural and electronic

properties of sub-stoichiometric NbCx and MoCx in the NaCl type structure using

an ab initio full-potential linear augmented plane wave method. A model structure

of 8 and 16 atom super-cells with ordered vacancies within the carbon sub-lattices

was used. It was found that the lattice parameters of the studied stoichiometries in

both MoCx and NbCx were smaller than that of ideal stoichiometric MoC and NbC.

The results were found to be in good agreement with experiment and with other

theoretical ab initio calculations.

Vacancy Effects on Structural and Electronic Properties of 4d Transition-Metal

Carbides. A.Zaoui, S.Kacimi, M.Zaoui, B.Bouhafs: Computational Materials

Science, 2009, 44[4], 1071-5