The band structure of non-stoichiometric layered diborides, Me0.75B2 (M = Nb, Zr, or Y), was calculated for the first time in the framework of the self-consistent full-potential linearized muffin-tin orbital method, and the energies of formation of metal vacancies were estimated numerically. It was established that metal vacancies affected the electronic properties and energy states of group III–V metal diborides in radically different ways.

Effect of Metal Vacancies on the Band Structure of Nb, Zr and Y Diborides. I.R.Shein, N.I.Medvedeva, A.L.Ivanovskiĭ: Physics of the Solid State, 2003, 45[9], 1617-21