Antimony selenide (Sb 2 Se 3 ) has been proposed as an alternative material for a wide range of applications; however, the electronic structure of the Sb 2 Se 3 lattice is not clearly known yet. As a consequence, there are abundant contradictory interpretations of experimental results leading to incoherent determinations of its energy band gap and the type of optical transitions. Moreover, Sb 2 Se 3 is recently being synthesized in different types of nanostructures; therefore, detailed knowledge of the bulk electronic structure is necessary to evaluate deviations due to confinement or surface effects. In this paper, we study the electronic band structure of antimony selenide using density functional theory (DFT) within the generalized gradient approximation (GGA) with GW corrections. Our calculations show that Sb 2 Se 3 has an indirect energy band gap of 1.21 eV; however, a direct transition only 0.01 eV higher than the band gap (1.22 eV) is also possible. The calculated density of states agrees well with the experiments reporting photoemission spectra.

Sub-10 nm semiconducting nanostructures are crucial for the realization of nanoscale devices. Fabrication of nanostructures at this scale with homogeneous properties is challenging. Using ab initio calculations, we show that self-standing ribbons of antimony selenide and antimony sulfide of width 1.1 nm exhibit well-defined bandgaps of 1.66 and 2.16 eV, respectively. Molecular dynamics studies show that these ribbons are stable at 500 K. The one-dimensional (1D) heterostructure of these nanoribbons (Sb(2)Se(3)/Sb(2)S(3)) along the [001] direction shows a straddling type behavior.

Magnetocrystalline anisotropy at Heusler alloy|MgO interfaces have been studied using first principles calculations. It is found that Co terminated Co2FeAl|MgO interfaces show perpendicular magnetic anisotropy up to 1.31 mJ/m 2 , while those with FeAl termination exhibit in-plane magnetic anisotropy. Layer resolved analysis indicates that the origin of perpendicular magnetic anisotropy in Co2FeAl|MgO interfaces can be attributed to the out-of-plane orbital contributions of interfacial Co atoms. At the same time, Co2MnGe and Co2MnSi interfaced with MgO tend to favor in-plane magnetic anisotropy for all terminations.