Orbital-Free Density Functional Theory: An Attractive Electronic Structure Method for Large-Scale First-Principles...

Area of Science:

• Computational Chemistry
• Materials Science
• Condensed Matter Physics

Background:

• Kohn-Sham Density Functional Theory (KSDFT) is widely used but computationally expensive for large systems.
• The high cost of KSDFT arises from calculating Kohn-Sham orbitals, limiting its application in large-scale simulations.
• Orbital-free DFT (OFDFT) eliminates the need for explicit orbital calculations, offering a more scalable approach.

Purpose of the Study:

• To review the historical context and theoretical foundations of OFDFT.
• To discuss the challenges and recent advancements in developing accurate kinetic energy density functionals (KEDFs) for OFDFT.
• To survey numerical techniques and applications of OFDFT in various scientific domains.

Main Methods:

• Review of existing literature on OFDFT and KEDFs.
• Analysis of different types of KEDFs, including one-point, two-point, and machine-learned functionals.
• Survey of numerical algorithms and implementation strategies for OFDFT.

Main Results:

• OFDFT achieves near-linear scaling with system size, significantly reducing computational cost compared to KSDFT.
• Progress has been made in developing approximate KEDFs, although challenges remain.
• Various KEDFs and numerical methods are being explored to enhance OFDFT accuracy and applicability.

Conclusions:

• OFDFT presents a promising avenue for simulating larger and more complex systems than currently feasible with KSDFT.
• Continued development of KEDFs and numerical methods is crucial for realizing the full potential of OFDFT.
• OFDFT applications are emerging in materials science, chemistry, and physics, enabling exploration of new phenomena.