Novel Accurate Coupled-Cluster Approach

Objective

The coupled-cluster family of methods is among the most reliable tools for treating weak and intermediate electron correlation. However, extensions of coupled-cluster theory to systems with strong correlation remain severely constrained by their high computational cost. I propose a novel accurate coupled-cluster approach (NovACCA) that overcomes these limitations by delivering a rigorous, balanced, and computationally affordable treatment of strong correlation. The objectives include (1) derive and implement such methods within the spin-flip framework; (2) validate and benchmark the methods against state-of-the-art theoretical and experimental data on transition-metal complexes; (3) derive density matrices for electronic-structure analysis and molecular properties; and (4) extrapolate effective Hamiltonians for the accurate description of multi-center transition-metal compounds and metal–organic frameworks. NovACCA will lead the PI to explore new opportunities for predictive modeling of magnetic materials, catalysts, and energy-relevant molecular systems.