Relativistic two-component projection-based quantum embedding for open-shell systems.

Area of Science:

• Quantum Chemistry
• Relativistic Quantum Mechanics
• Computational Chemistry

Background:

• Relativistic effects significantly influence the electronic structure of heavy elements.
• Accurate modeling of these effects is essential for understanding chemical properties.
• Existing quantum embedding methods often struggle to incorporate relativistic phenomena comprehensively.

Purpose of the Study:

• To develop a relativistic quantum embedding formalism that variationally treats scalar-relativity and spin-orbit coupling.
• To extend density functional theory (DFT)-in-DFT projection-based quantum embedding to a relativistic two-component framework.
• To provide a robust tool for modeling molecular complexes with heavy elements.

Main Methods:

• Implementation of a relativistic two-component formalism within a DFT-in-DFT projection-based quantum embedding scheme.
• Retaining the full spin magnetization vector form throughout the embedding treatment.
• Benchmarking relativistic embedding schemes using specific molecular examples.

Main Results:

• Demonstrated capability to treat scalar-relativity and spin-orbit coupling variationally.
• Successful application to benchmark systems including W(CO)6, a dinuclear chromium complex, and WF6.
• Validation of the formalism for diverse relativistic phenomena in molecular systems.

Conclusions:

• The developed relativistic quantum embedding formalism is well-suited for accurate modeling.
• Efficiently handles open-shell systems with late transition metals, lanthanides, and actinides.
• Offers a powerful computational tool for advancing the study of heavy element chemistry.