In this study, we employed ChatGPT, the May 12 version, an LLM with knowledge spanning various technical disciplines, including chemistry and programming, as a new approach to molecular descriptor selection. In response to the initial question regarding the theoretical formula to determine the refractive index, GPT-4 accurately identified the Lorentz-Lorenz equation as a key determinant (Fig. ). As this equation is one of the most common formulas used for predicting the molecular refractive index, this verified GPT -4's capability to provide pertinent insights.