Coupled-Cluster Theory for Ground and Excited Eigenstates

Explore the intricacies of single-reference coupled-cluster theory in this 48-minute lecture by Andre Laestadius from OsloMet. Delve into the reformulation of the Schrödinger equation into a polynomial system using the exponential ansatz. Examine how cluster amplitudes correspond to ground and excited eigenstates of the Schrödinger operator. Investigate various coupled-cluster approach variants, including extended and tailored methods. Gain insights into the establishment of existence and error estimates for approximate solutions, as well as numerically observed behaviors in coupled-cluster theory.