Anharmonic theoretical simulations of infrared spectra of halogenated organic compounds.

The recent implementation of the computation of infrared (IR) intensities beyond the double-harmonic approximation [J. Bloino and V. Barone, J. Chem. Phys. 136, 124108 (2012)] paved the route to routine calculations of infrared spectra for a wide set of molecular systems. Halogenated organic compounds represent an interesting class of molecules, from both an atmospheric and computational point of view, due to the peculiar chemical features related to the halogen atoms. In this work, we simulate the IR spectra of eight halogenated molecules (CH2F2, CHBrF2, CH2DBr, CF3Br, CH2CHF, CF2CFCl, cis-CHFCHBr, cis-CHFCHI), using two common hybrid and double-hybrid density functionals in conjunction with both double- and triple-ζ quality basis sets (SNSD and cc-pVTZ) as well as employing the coupled-cluster theory with basis sets of at least triple-ζ quality. Finally, we compare our results with available experimental spectra, with the aim of checking the accuracy and the performances of the computational approaches.