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The structural, elastic, electronic, and thermodynamic properties of a LiScSi1−xCx alloy in the α-phase were investigated using density functional theory with the plane-wave pseudopotential method and the alchemical mixing approximation in ABINIT code. We computed ground-state properties including lattice constants, bulk modulus, energy gap, refractive index, and optical dielectric constant for the LiScSi1−xCx compounds. Our results align well with existing theoretical data for the parent compounds LiScSi and LiScC. We found that the fundamental bandgap for the α-LiScSi1−xCx alloy varied from 0.865 eV to 1.143 eV using the B3LYP approach, indicating potential applications in optoelectronic devices such as photodetectors and light-emitting diodes (LEDs), where precise control over electronic and optical properties is crucial. Additionally, we calculated the electron and hole effective masses, which showed a decrease with increasing carbon concentration; the electron effective mass ranged from 0.042m* for LiScSi to 0.035m* for LiSiC. The LiScSi1−xCx alloy in the α-phase consistently exhibited direct semiconductor behavior (X → X) across all concentrations. We also predicted the variation in thermodynamic properties, including unit cell volume, bulk modulus, heat capacity, and thermal expansion coefficient, with temperature for various carbon concentrations. These findings contribute to a deeper understanding of the material's potential applications in electronic and thermoelectric devices. [ABSTRACT FROM AUTHOR]

We report on structural properties, elastic constants, mechanical and dynamical stabilities, electronic band structure, and hydrogen storage applications of Mg2FeH6 at zero and high-pressure effects. The work has been realized within the full-potential linearized augmented plane wave method. At zero pressure, the material under study is stable and has a ductile nature. The electronic structure of the material of interest is determined to be X-X wide direct band gap semiconductor with an energy of 1.88 eV. The hydrogen storage capacity wt (%) and the hydrogen desorption temperature are reported as 5.473 and 625.47 K respectively. The Debye temperature ϴD is recorded as 698 K using the elastic constants and about 775 K using the Gibbs calculations. Under high-pressure effect up to 80 GPa, the semiconductor still be an X-X semiconductor with an energy gap of 3.91 eV. The Debye temperature ϴD increases monotonically up to about 1120 K at 80 GPa when using the calculated elastic constants whereas the desorption temperature decreases from 650 to 0 K by increasing pressure from 0 to about 87 GPa. [ABSTRACT FROM AUTHOR]