An Insight into the Structural, Electronic and Transport Characteristics of XIn_(2)S_(4) (X = Zn, Hg) Thiospinels using a Highly Accurate All-Electron FP-LAPW+Lo Method

The highly accurate full-potential linearized augmented plane wave plus local orbital method is employed to calculate the structural,electronic and transport properties of HgIn_(2)S_(4) and ZnIn_(2)S_(4).For ZnIn_(2)S_(4),the calculated In–S bond length is in good agreement with the experimental data.Bulk moduli results suggest that ZnIn_(2)S_(4) can afford more compressional effects than HgIn_(2)S_(4).The present study confirms that both HgIn_(2)S_(4) and ZnIn_(2)S_(4) are indirect band gap materials with band gap values of 0.705 eV and 1.533 eV respectively.The localized region existing in the most bottom valance band of both materials splits into states by 1 eV energy difference under the spin orbital coupling effect.Contour plots of charge density predict that chemical bonding in these compounds is a mixture of ionic and covalent characteristics.Effective mass results reveal that mobility of charge carriers in ZnIn_(2)S_(4) is greater than that in HgIn_(2)S_(4).