Author(s)

Blaise Awola Ayirizia¹, Yuriy Malozovsky¹, Lashounda Franklin¹, Uttam Bhandari², Diola Bagayoko¹

¹Department of Mathematics and Physics, Southern University and A&M College, Baton Rouge, LA, USA.
²Department of Computer Science, Southern University and A&M College, Baton Rouge, LA, USA.

We report results on electronic, transport, and bulk properties of rock-salt magnesium selenide (MgSe), from density functional theory (DFT) calculations. We utilized a local density approximation (LDA) potential and the linear combination of atomic orbitals formalism (LCAO). We followed the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF), to perform a generalized minimization of the energy, down to the actual ground state of the material. We describe the successive, self-consistent calculations, with augmented basis sets, that are needed for this generalized minimization. Due to the generalized minimization, our results have the full, physical content of DFT, as per the second DFT theorem [AIP Advances, 4, 127104 (2014)]. Our calculated, indirect bandgap of 2.49 eV, for a room temperature lattice constant of 5.460 Å, agrees with experimental findings. We present the ground-state band structure, the related total and partial densities of states, DOS and PDOS, respectively, and electron and hole effective masses for the material. Our calculated bulk modulus of 63.1 GPa is in excellent agreement with the experimental value of 62.8 ± 1.6 GPa. Our predicted equilibrium lattice constant, at zero temperature, is 5.424 Å, with a corresponding indirect bandgap of 2.51 eV. We discuss the reasons for the agreements between our findings and available, corresponding, experimental ones, particularly for the band gap, unlike the previous DFT results obtained with ab-initio LDA or GGA potentials.

Density Functional Theory, Generalized Energy Minimization, Ground State Band Structure, Band Gap, Related Properties

Ayirizia, B. , Malozovsky, Y. , Franklin, L. , Bhandari, U. and Bagayoko, D. (2020) Ab-Initio Self-Consistent Density Functional Theory Description of Rock-Salt Magnesium Selenide (MgSe). Materials Sciences and Applications, 11, 401-414. doi: 10.4236/msa.2020.117027.