Random Structure Searching with Orbital-Free Density Functional Theory.

Area of Science:

• Materials Science
• Computational Chemistry
• Condensed Matter Physics

Background:

• Predicting material properties requires understanding atomic arrangements, a complex challenge.
• Orbital-free density functional theory (OF-DFT) offers a computationally efficient quantum mechanical model based on electron density.

Purpose of the Study:

• To employ OF-DFT with random structure searching to map low-energy crystal structures.
• To investigate the crystal structures of Lithium (Li), Sodium (Na), Magnesium (Mg), and Aluminum (Al) at zero pressure.

Main Methods:

• Utilizing orbital-free density functional theory (OF-DFT) for quantum mechanical calculations.
• Implementing a random structure searching strategy involving relaxation of atomic configurations to energy minima.

Main Results:

• Successfully mapped low-energy crystal structures for Li, Na, Mg, and Al.
• Identified numerous near-equal energy close-packed polytypes for Li and Na.
• Unambiguously determined ground state structures for Mg and Al, alongside other low-energy configurations.

Conclusions:

• OF-DFT combined with random structure searching is effective for predicting crystal structures.
• This approach accelerates the discovery of new materials and understanding of existing ones.
• Continued advances in OF-DFT accuracy will further enhance its utility across diverse chemical compositions and pressures.