On using DFT to construct an IR spectrum database for PFAS molecules

PFAS molecules are chain-linked carbon/fluorine atoms, widely distributed in the environment, and dangerously toxic biologically. Here is constructed, using density functional theory (DFT), a prototype database of IR spectra for detection of PFAS molecules. Extraction of spectrum features for target molecules from measured spectra can be achieved by comparison to template spectra within a spectrum database, which are sufficient approximations of target spectra. The concept of extracting spectral features is distinct from that of inverting reflectance or transmission spectra for determination of dielectric response functions. This study continues presentation of the concept of using DFT to calculate template spectra for practical detection of target substances, by comparison with spectra within databases. Specifically, the focus here is upon PFAS molecules, which include toxic and carcinogenic environmental contaminants, and whose detection based on IR spectroscopy is thus of great importance.