Assessment of long-range corrected functionals for the prediction of non-linear optical properties of organic materials

We calculate the hyperpolarizability of the prototypical chromophore p-nitroaniline in gas phase using different long-range corrected Density Functional Theory (LC-DFT) methods and compare it with experimental data. While traditional DFT methods are inadequate for predicting hyperpolarizabilities, LC-DFT functionals provide very good agreement with experiment (less than 10% error) for this archetypal organic molecule with large nonlinear optical (NLO) susceptibility. Additionally, we use the LC- ω PBE functional to calculate the structures and predict the hyperpolarizabilities of two recently synthesized potential organic NLO materials. The structures are compared with experimental measurements and found to be in excellent agreement.