Abstract
We report on ab-initio all electrons spin-polarised density-functional calculations for the band structure, optical spectra and magnetisation of bulk MnAs with NiAs-type lattice structure with emphasis on their dependence on pressure. The aim of this contribution is to show how the investigated properties behave upon compression. Our findings are compared when possible with those reported in the literature showing generally reasonable accordance. Our results indicate that the material under load exhibits a metallic character. The studied optical spectra show an anisotropic character between thexandzdirections and are shifted downwards with raising pressure. The predicted static refractive index values depend on the direction, spin channel and pressure. The effect of the spin channel on the electronic and optical properties is found to be important. At zero pressure, MnAs reaches a total magnetic moment of the order of 5.69 mu(B)per cell which decreases with raising pressure. The material of interest can be regarded as a good candidate for use in fabricating novel functional materials due to the spin degree of freedom.