Infrared absorption cross section and radiative forcing efficiency features of four hydrofluoropolyethers: Performance of some DFT functionals

Abstract

The present work aimed to investigate the infrared absorption cross section spectra using a series of eight DFT methods including DSD-PBEP86, B2PLYP, B3LYP, BLYP, G96LYP, M06-L, PBEPBE, and TPSSTPSS with basis sets Def2-TZV and Def2-TZVP. These were assigned to a series of four H-Galdens noted HG-00, HG-10, HG-01, and HG-11. The experimental infrared spectra of these gases provided by Myhre et al. [Atmos. Environ. 33 (1999) 4447] are well reproduced using the method M06-L/Def2-TZVP over the frequency range 0–3200 cm−1. The radiative forcing efficiency, descriptor of climate effect, was estimated using the narrow band model and corrected with a lifetime factor for different computational methods. The double hybrid functionals yield accurate results compared to experiment in the range 0–2500 cm−1 for HG-00, HG-10, and HG-01, and in the range 600–1600 cm−1 for HG-11. The other functionals are in good agreement over the specific frequency ranges.