Current density functional framework for spin-orbit coupling: Extension to periodic systems.

Area of Science:

• Quantum Chemistry
• Condensed Matter Physics
• Materials Science

Background:

• Spin-orbit coupling (SOC) is crucial for understanding electronic properties in materials.
• Current density in the ground state necessitates advanced density functional approximations.
• Existing meta-generalized gradient approximations (meta-GGAs) do not fully account for SOC-induced current densities.

Purpose of the Study:

• To generalize the spin-orbit current density functional theory (SOC-CDFT) formalism.
• To extend the formalism to non-magnetic and magnetic periodic systems of arbitrary dimensions.
• To implement analytical derivatives for calculating geometry gradients and stress tensors.

Main Methods:

• Generalization of meta-generalized gradient approximations to include current density.
• Development of a formalism for spin-orbit current density functional theory in periodic systems.
• Implementation of analytical derivatives for geometry optimization and stress tensor calculations.

Main Results:

• The generalized SOC-CDFT formalism is applicable to periodic systems.
• Analytical derivatives enable efficient structural property calculations.
• The impact of current density on band gaps, lattice constants, magnetic transitions, and Rashba splittings is quantified.

Conclusions:

• The developed SOC-CDFT provides a more accurate description of electronic properties in periodic systems.
• Current density plays a significant role in various material properties, sometimes exceeding differences between standard DFT approximations.
• This work offers a robust theoretical framework for studying SOC effects in condensed matter systems.