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Title: Isotope Effects in the Zundel–Eigen Isomerization of H+(H2O)6

Journal Article · · Journal of Physical Chemistry Letters

The isomerization pathway between the energetically low-lying Zundel and Eigen isomers of the protonated water hexamer was investigated using high-level ab initio calculations including a treatment of zero-point corrections. On the basis of these calculations, the Zundel–Eigen isomerization was found to proceed through a stable intermediate isomer, which consists of a four-membered ring with two single acceptor water molecules. Further, the inclusion of vibrational zero-point energy is shown to be important for accurately establishing the relative energies of the three relevant isomers involved in the Zundel–Eigen isomerization. Diffusion Monte Carlo calculations including anharmonic vibrational effects show that all three isomers of H+(H2O)6 and D+(D2O)6 have well-defined structures. The energetic ordering of the three isomers changes upon deuteration. The implications of these results for the vibrational spectra of H+(H2O)6 and D+(D2O)6 are also discussed.

Research Organization:
Univ. of Pittsburgh, PA (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); National Science Foundation (NSF)
Grant/Contract Number:
SC0021065; CHE-1624430; AC02-05CH11231; AC05-76RL01830; SC0021081; FWP 16249; OAC-2117681
OSTI ID:
1993717
Alternate ID(s):
OSTI ID: 1984270
Report Number(s):
PNNL-SA-184043
Journal Information:
Journal of Physical Chemistry Letters, Vol. 14, Issue 20; ISSN 1948-7185
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

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