<i>Ab-Initio</i>Self-Consistent Density Functional Theory Description of Rock-Salt Magnesium Selenide (MgSe)

• 作者: Blaise Awola Ayirizia Diola Bagayoko Lashounda Franklin Uttam Bhandari Yuriy Malozovsky
• 来源期刊: 材料科学与应用期刊(英文)
• 学科: 数学
• 关键词: Density Functional Theory Generalized Energy Minimization Ground State Band Structure Band Gap Related Properties
• 年，卷（期）: clkxyyyqkyw_2020,（7）
• 页码范围: 401-414
• 页数: 14页
• 分类号: O17

摘要

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 <span style="white-space:nowrap;">&Aring;</span>, 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 <span style="white-space:nowrap;">&Aring;</span>, 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.