Investigation of vacancy in C54 TiSi2 using ab initio method

Investigated by ab initio plane-wave ultrasoft pseudopotential method based on generalized gradient approximation (GGA), it has been found that the formation energies of the vacancies in C54 TiSi2 largely depend on the atomic chemical potentials of Ti and Si. In Si-rich limit, the formation energies of the Si and Ti vacancy are 2.39 eV and 2.40 eV while they are 1.53 eV and 4.07 eV in Ti-rich limit, respectively. The introduction of Si or Ti vacancy only slightly changes total density of states (DOS) and it also causes no considerable charge transfer.