First principles study on structural, phase transition and electronic structure of Zinc Sulfide (ZnS) within LDA, GGA and mBJ potential

An ab-initio calculation based on full potential linearised augmented plane wave method of density functional theory (DFT) within the localised density approximation (LDA), generalised gradient approximation (GGA) and modified Becke-Johnson (mBJ) for exchange correlation potential is performed to investigate the structural, phase transition and electronic structure of Zinc Sulfide (ZnS). A comparative study is performed for the three approximations and reveal that calculations within the GGA gives better structural stability and phase transition pressure of 17.6 GPa in reasonably close agreement to experimental results. The electronic structure calculation within mBJ predicts higher direct band gap of 3.5eV in comparison to LDA and GGA underestimated value. The trend in the accuracy of energy band gap calculation is found to be LDA<GGA< mBJ-GGA. The electronic band structures are investigated using the total and partial density of states.