Antoine Aerts, P. Carbonnière, F. Richter, and Alex Brown
J. Chem. Phys. 152, 024305 (2020)
Publication year: 2020

The vibrational eigenenergies of the deuterated forms of formic acid (DCOOD, HCOOD, and DCOOH) have been computed using the block-improved relaxation method as implemented in the Heidelberg multi-configuration time-dependent Hartree package on a previously published poten- tial energy surface [J. Chem. Phys. 148, 064303 (2018)] generated at the CCSD(T)-F12a/aug-cc- pVTZ-F12 level of theory. Fundamental, combination band, and overtone transition frequencies of the trans isomer were computed up to ∼ 3000 cm-1 with respect to the zero point energy and assignments were determined by visualisation of the reduced densities. Root mean square de- viation of computed fundamental transition frequencies with experimentally available gas-phase measurements are 8, 7, and 3 cm-1 for trans- DCOOD, HCOOD, and DCOOH, respectively. The fundamental transition frequencies are provided for the cis isomer of all deuterated forms; experimental measurements of these frequencies for the deuterated cis isotopologues are not yet available and the present work may guide their identification.