# Vibrational Properties DFT vibrational frequency analyses produce a set of frequencies, their predicted spectroscopic activities and intensities, and the vibrational normal modes associated with each frequency. From these individual components, we report predicted infrared spectra. In DFT, the reported frequencies are reported as single numerical values, leading to IR spectra with infinitely thin peaks (so-called "stick spectra"). On the Materials Project Web site, we allow users to visualize the computed IR spectra with broadened peaks based on Gaussian and Lorentzian lineshapes. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.materialsproject.org/methodology/molecules-methodology/vibrational-properties.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.