Strong Correlation in Molecules: Valence Bonds and Cooper Pairs
Paul Johnson
Département de Chimie, Université de Laval, Québec Canada
Mercredi 9 Octobre 2024, 14H00
Bibiothèque du LCT, Couloir 12-13, 4ème étage, Campus Pierre et Marie Curie
Equilibrium geometries of molecules are well described as weakly correlated electrons around the nuclei. Qualitatively these systems are described by one molecular orbital (MO) diagram, while a quantitative result is obtainable with a small number of MO diagrams. This is not the case when bonds are stretched or broken. Many MO diagrams would be required and the physical picture is thus not weakly correlated electrons. For such cases we have shown that Richardson-Gaudin states are a much better starting point. They represent weakly correlated pairs of electrons. Simple corrections are shown to account for the remaining effects.