The electrical and optical properties of lithium niobate $\left({\mathrm{LiNbO}}_3\right)$ at room temperature are theoretically calculated by using a microscopic model based on the orbital approximation in correlation with the dipole-dipole interaction. It is found that both the electronic polarizabilities and the electronic hyperpolarizabilities have to be considered in this calculation in order to match both the spontaneous polarization and refractive indices with experimental data.

• Received 2 January 2003

DOI:https://doi.org/10.1103/PhysRevB.67.174109