Size Extensivity & Coupled Cluster Theory

This lecture covers the concepts of size extensivity and size consistency in quantum chemistry, emphasizing the correct linear scaling with the number of electrons. It also delves into the principles of coupled cluster theory, explaining the van Vleck principle, complexity, and size extensivity. The instructor discusses the advantages of the exponential form in coupled cluster calculations and the importance of coupled cluster energy. The lecture concludes with insights on coupled cluster amplitudes, convergence, and scaling in quantum chemistry.