Transferable local pseudopotentials for magnesium, aluminum and silicon

Area of Science:

• Computational Materials Science
• Quantum Chemistry
• Condensed Matter Physics

Background:

• Accurate local pseudopotentials (LPSs) are crucial for orbital-free density functional theory (OF-DFT).
• Existing LPSs often lack accuracy and transferability, limiting OF-DFT applications.
• Developing reliable LPSs is key to advancing large-scale first-principles simulations.

Purpose of the Study:

• To construct high-quality, transferable local pseudopotentials (LPSs) for Mg, Al, and Si.
• To validate these LPSs in Kohn-Sham Density Functional Theory (KS-DFT) calculations for various material properties.
• To assess the performance of OF-DFT using these new LPSs for large-scale simulations.

Main Methods:

• Inverting Kohn-Sham (KS) equations using bulk valence electron densities to generate atom-centered LPSs.
• Testing LPSs in KS-DFT for static bulk properties, surface energies, point defects, and stacking faults.
• Performing OF-DFT calculations with the Wang-Govind-Carter (WGC) nonlocal kinetic energy density functional (KEDF).

Main Results:

• Mg, Al, and Si LPSs accurately predict ground state properties and phase orderings.
• KS-DFT calculations using these LPSs show quantitative agreement with nonlocal pseudopotentials (errors ≤ 40 meV/atom).
• OF-DFT simulations with new LPSs and WGC KEDF closely match KS-DFT results for Mg and Al structures.

Conclusions:

• The developed Mg, Al, and Si LPSs are accurate and transferable for KS-DFT.
• OF-DFT, utilizing these LPSs and the WGC KEDF, offers a practical approach for large-scale simulations.
• This advancement significantly enhances the capability of OF-DFT for studying main group metals and alloys.