Full Coupled-Cluster Reduction for Accurate Description of Strong Electron Correlation

Area of Science:

• Quantum Chemistry
• Computational Physics
• Theoretical Chemistry

Background:

• Accurate solutions to the many-body Schrödinger equation are crucial in quantum chemistry.
• Traditional coupled-cluster methods can be computationally intensive for large systems.

Purpose of the Study:

• To develop a computationally efficient full coupled-cluster expansion.
• To achieve highly accurate solutions for the many-body Schrödinger equation using sparse algebraic operations.

Main Methods:

• Explicitly expanding Baker-Campbell-Hausdorff series commutators for cluster operators in binary representations.
• Implementing screenings on the projection manifold and commutator operations for reduction.
• Iteratively updating the projection manifold using single commutators of primary clusters.

Main Results:

• A full coupled-cluster reduction method is developed, suitable for sparse algebraic operations.
• The method provides very accurate solutions to the many-body Schrödinger equation.
• Inclusion of exclusion-principle-violating terms leads to fast and near-variational convergence.

Conclusions:

• The developed coupled-cluster expansion offers an efficient and accurate approach for solving the many-body Schrödinger equation.
• The method's efficiency is enhanced by utilizing sparse algebraic operations and specific computational strategies.
• This work contributes to advancing computational methods in quantum chemistry and related fields.