Quantum Calculation of the Second-Order Hyperpolarizability of Chiral Molecules in the One-Electron Model

Quantum calculation of the hyperpolarizabilty tensor is carried out for chiral molecules displaying a one-electron chirality. Calculation is made possible by introducing a chiral perturbation term in the potential energy surface. We show that a one-electron chiral molecule is intrinsically nonlinear and diplays a nonzero electric chiral hyperpolarizability. Existence of magnetic contributions is discussed, and it is shown that higher-order perturbation terms arc necessary to introduce such magnetic effects in the second-order hyperpolarizability.