Hopping of Li@AR (AR = Benzene and Naphthalene) between Electride and Lithium Salt Configurations Brings Considerably Different First Hyperpolarizabilities: Candidate for High-Performance Nonlinear Optical Molecular Switches

For Li@AR (AR = benzene and naphthalene), it is reported that hopping of Li atom under the external electric field between electride and lithium salt configurations brings decidedly different charge transfer directions, that is, perpendicular (electride) or parallel (lithium salt) to the direction of dipole moment orientation, in the crucial transitions, and subsequently, the considerably different static first hyperpolarizabilities (beta(0)) are exhibited. From electride to lithium salt configurations, the rise of beta(0 )value constitutes an order of magnitude improvement. Especially, the beta(0) value is increased approximately 34-fold from 1425 au (electride) to 49,746 au (lithium salt) for Li@benzene. These different extremely large beta(0) values between them reinforce the potential of these simple systems for application in nonlinear optics switch.