Using SCF metadynamics to extend density matrix embedding theory to excited states.

Area of Science:

• Quantum Chemistry
• Computational Physics
• Electronic Structure Theory

Background:

• Density Matrix Embedding Theory (DMET) is effective for ground state energies in strongly correlated systems.
• DMET has not been previously applied to calculating excited electronic states.
• Accurate excited state calculations are crucial for understanding molecular and material properties.

Purpose of the Study:

• To propose and implement a novel framework for directly targeting excited electronic states using DMET.
• To adapt the DMET methodology for excited state energy calculations.
• To assess the feasibility and identify challenges of the excited state DMET approach.

Main Methods:

• Developed a new framework based on Density Matrix Embedding Theory (DMET).
• Applied Schmidt decomposition directly to excited states, approximated by higher self-consistent field solutions.
• Integrated the DMET prescription following Schmidt decomposition for direct excited state embedding.

Main Results:

• Successfully implemented an excited state DMET framework.
• Obtained initial results for multiple hydrogen dimers and lithium hydride dissociation.
• Analyzed the components of the excited state DMET calculation and identified key challenges.

Conclusions:

• The proposed excited state DMET framework is a novel approach for electronic structure calculations.
• The study highlights challenges in the implementation of excited state DMET.
• Recommendations for future development and overcoming identified challenges are provided.