The band gap of II-VI ternary alloys in a tight-binding description

\Ve prescnt tight-binding calculations for the hand gap 01' JI-VI pseudohinary ternary alloys. We use an .'iJ,3.'l. tight-hinding Hamiltonian which indude spin-orhit coupling. The band gap colllposition dependence is calculated using a eXlended version of the virtual crystal appro:-::imalion, which introduce an empirical corrcclion f<lctor that takes into ac('(mll( the non-linear dcpcndcnce of the hand gap with the cnmposition. Thc rcsults comp<lre quite well with the experimental data. holh for Ihe ternary alloys wilh wide hand gap and for the narro\\' hand gap ones.