Perturbation theory in chemistry

Perturbation theory in chemistry is a method used to estimate how a small change in a system affects its overall energy or behavior. It's like starting with a well-understood problem and then adding a slight modification, allowing scientists to predict complex interactions—such as electron interactions within molecules—without solving the entire problem from scratch. This approach simplifies calculations of molecular properties by considering the effect of these small "perturbations," helping chemists understand and predict chemical behavior more efficiently.