Vibrational states of deuterated trans - and cis -formic acid: DCOOH, HCOOD, and DCOOD

Antoine Aerts (1, 2) , Philippe Carbonnière (3) , Falk Richter (3) , Alex Brown (2)

1 ULB - Université libre de Bruxelles
2 University of Alberta
3 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

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 multiconfiguration time-dependent Hartree package on a previously published potential energy surface [F. Richter and P. Carbonnière, 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 visualization of the reduced densities. Root mean square deviations of computed fundamental transition frequencies with experimentally available gas-phase measurements are 8, 7, and 3 cm-1 for trans-DCOOD, trans-HCOOD, and trans-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.

Mots clés: Formic acid; Isomers; Molecular physics; Phase measurement; Potential energy; Quantum chemistry

Domaines: Chimie théorique et/ou physique

Antoine Aerts, Philippe Carbonnière, Falk Richter, Alex Brown. Vibrational states of deuterated trans - and cis -formic acid: DCOOH, HCOOD, and DCOOD. Journal of Chemical Physics, 2020, 152 (2), pp.024305. ⟨10.1063/1.5135571⟩. ⟨hal-02464246⟩