Density Matrix Renormalization Group Approach Based on the Coupled-Cluster Downfolded Hamiltonians.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Accurately simulating complex electronic systems requires methods that capture both static and dynamic electron correlation.
• Traditional methods often struggle with the computational cost associated with strong correlation.
• Developing efficient and accurate computational tools is crucial for understanding chemical processes.

Purpose of the Study:

• To develop and validate a computational approach integrating Hermitian coupled-cluster downfolding with the Density Matrix Renormalization Group (DMRG).
• To accurately treat static and dynamic electron correlations in challenging electronic systems.
• To provide a robust tool for simulating strongly correlated molecules.

Main Methods:

• Integration of a Hermitian coupled-cluster downfolding technique.
• Application of the Density Matrix Renormalization Group (DMRG) for ground-state energy calculations.
• Active-space Hamiltonian construction for targeted electronic correlation treatment.

Main Results:

• Accurate calculation of ground-state energies for active-space Hamiltonians.
• Successful demonstration on molecular benchmarks: N2, benzene, porphyrin, and tetramethyleneethane.
• Efficient treatment of both static and dynamic correlations in the tested systems.

Conclusions:

• The combined coupled-cluster downfolding and DMRG approach provides an accurate and efficient method for strongly correlated systems.
• This integrated technique represents a significant advancement in computational chemistry.
• The method shows promise for simulating complex chemical processes and materials.