Croatica Chemica Acta, Vol. 97 No. 4, 2024.
Original scientific paper
https://doi.org/10.5562/cca4132
Tunneling Splittings of the Protonated Water and Water Dimer
Tea Babić
; Faculty of Science, University of Zagreb, Department of Physics, Bijenička cesta 32, 10000, Zagreb, Croatia
Mihael Eraković
; Ruđer Bošković Institute, Department of Physical Chemistry, Bijenička cesta 54, 10000, Zagreb, Croatia
Marko T. Cvitaš
; Faculty of Science, University of Zagreb, Department of Physics, Bijenička cesta 32, 10000, Zagreb, Croatia
*
* Corresponding author.
Supplements: cca4132_supplement.pdf
Abstract
Tunneling splittings (TS) in the ground state (GS) and selected vibrationally excited states of hydronium and Zundel cation are determined using the recently-developed Jacobi fields instanton method in full dimensionality and results compared to the previous numerically exact calculations. It is found that the TSs for the states that have higher energy than the barrier height can still be accurate and follow the correct trends (relative to the GS TS) if the contribution of the transverse modes dominates the splitting. Rearrangements between adjacent minima in Zundel cation have been studied in terms of minimum-action paths. TSs due to monomer inversion and internal rotation have been converged for the GS and the excited lowest-frequency mode. Observation of the fine splittings in the lowest branch of its TS pattern due to bifurcations, which break bonds to the shared proton, is precluded by symmetry.
Keywords
instanton theory; tunneling splittings; vibrational spectra; WKB; semiclassical vibrational dynamics; quantum molecular dynamics; bound states; protonated water clusters
Hrčak ID:
327168
URI
Publication date:
21.11.2024.
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