Summary Exploration of the potential energy surface (PES) is a very common task in molecular modeling. The task is often addressed by recording the change of energy along a particular molecular coordinate, while at the same time keeping the rest of the coordinates frozen or letting them relax (rigid and relaxed coordinate scans, respectively). This procedure is attractive because it is automated and systematic. The use of PES scans in practice is, however, not always straightforward. Questions arise as to the choice between rigid and relaxed scans, the choice of the basis set and density functional, the convergence of the self-consistent equations and the artifacts introduced by the restricted and unrestricted orbitals while stretching bonds, etc. Additional complications are encountered when working with transition metal complexes and protein systems. In this webinar we are going to discuss these questions with the help of coordinate scans as implemented in the quantum chemical codes Jaguar and QSite. Dihedral scans in the study of atropisomerism and their application to understanding binding modes in proteins will be used as illustrations.
