Hydrostatic-pressure-dependent electronic and optical properties of tungstate MnWO4: A first-principles study

The dependence of electronic structure and optical properties of tungstate MnWO4 on hydrostatic pressure is presented using the first-principles method based on density functional theory. The calculation results show that the energy band gap of MnW4 decreases along three different stages with pressure increasing, from which it is deduced that the material will transform into the metal state at about 134.7 Gpa. Meanwhile, the crystal structure of MnWO4 also undergoes three different stages. Besides, it is found that the energy range of Mn 3d states and O 2s states expand gradually with pressure as well the peak of them reduce accordingly. In addition, the results show that the peaks' position in the imaginary part of dielectric function and the absorption band edge of MnWO4 are also influenced by the external pressure.