Perfluoroalkanes are potent greenhouse gases with long-term global warming impacts, which can be quantified using infrared absorption cross-section measurements. While measuring the cross-sections for the heavy perfluoroalkanes, we found that our perfluoro-n-pentane cross-sections differed significantly from those available on the high-resolution transmission molecular absorption (HITRAN) database. We investigated this discrepancy using theoretical cross-sections from density functional theory (DFT).
This talk will cover the basics of DFT, running a calculation using the ORCA software package, and calibration of the theoretical cross-section to best match experimental results. We will discuss the DFT results for all conformers of perfluoro-n-pentane, and consider the cause of the discrepancy between our and the HITRAN cross-sections.