Nonlocal Orbital-Free Kinetic Energy Functional from the Jellium-with-Gap Model for Finite Systems

Area of Science:

• Computational materials science
• Quantum chemistry
• Condensed matter physics

Background:

• Orbital-free density functional theory (OF-DFT) offers computational efficiency for large systems.
• Accurate kinetic energy density functionals are crucial for OF-DFT, especially for finite systems.
• Nonlocal kinetic energy density functionals (NL-KEDFs) are key to improving OF-DFT's applicability.

Purpose of the Study:

• Develop a novel NL-KEDF for accurately describing finite systems.
• Extend the utility of OF-DFT to molecular clusters and diverse density regimes.
• Enhance the computational framework for nanomaterial design and nanoscale phenomena.

Main Methods:

• Formulation of an NL-KEDF based on the linear-response kernel from the jellium-with-gap model (JGM).
• Benchmark calculations on finite systems, including molecular clusters.
• Analysis of Pauli potentials to assess functional accuracy.

Main Results:

• The proposed NL-KEDF accurately describes diverse density regimes in finite systems.
• Achieved higher accuracy compared to existing state-of-the-art orbital-free methods.
• Computed optical properties show good agreement with reference data, demonstrating reliability.

Conclusions:

• The developed NL-KEDF provides a robust and efficient extension of OF-DFT for finite systems.
• This advancement facilitates accurate modeling for nanomaterial design.
• Enables a deeper understanding of nanoscale phenomena through improved computational methods.