Comparative first-principle analysis of un-doped and V3+-doped α-ZnAl2S4 spinel

► Experimental and theoretical studies of α-ZnAl2S4 and α-ZnAl2S4:V3+ crystals were carried out. ► Ab inito and crystal field calculations were used in structural and spectroscopic analyses. ► The complete energy level scheme of the α-ZnAl2S4:V3+ system was suggested. ► The lowest vanadium 3d states are located at about 1.36 eV above the valence band's top.