Designing a novel material with considerable nonlinear optical responses based on the bicorannulenyl molecule.

In this work, a series of molecules decorated with Li atom and donor/acceptor have been theoretically designed based on bicorannulenyl molecule, where incorporating Li and different substitution are used as an effective strategy for enhancing nonlinear optical response. The mixed method is constructed through incorporating the Li and NO/NH substitution. To ensure accuracy, results were compared with another two functionals. As expected, data from three different functional approximations indicate that these molecules have large first hyperpolarizability. The calculation proves that these molecules exhibit large first hyperpolarizability in the range of 1956-37,758 au. For Li doped systems, by analyzing NBO, charge transfer occurs in studied molecules, which helps to get large nonlinear optical response. It is revealed that when Li atom is introduced into the molecule with only NO/NH substitution, the first hyperpolarizability increases significantly. Compared with Li doped and NO substitution, incorporating Li and NH substitution can be more powerful in increasing the first hyperpolarizabilities of bicorannulenyl molecule. In addition, the number of NH substitutions can more effectively enhance the first hyperpolarizability. We hope that this study could provide a new idea for designing nonlinear optical materials using bicorannulenyl molecule.