Structure and thermodynamics of H3O+(H2O)8 clusters: A combined molecular dynamics and quantum mechanics approach

Authors

Berhane TemelsoFollow
Thorsten Koddermann, SCAIFollow
Karl K. Kirschner, SCAIFollow
Katurah L. Klein, Bucknell UniversityFollow
George C. Shields, Bucknell UniversityFollow

Publication Date

2013

Description

We have studied the structure and stability of (H₃O⁺)(H₂O)₈ clusters using a combination of molecular dynamics sampling and high-level ab initio calculations. 20 distinct oxygen frameworks are found within 2 kcal/mol of the electronic or standard Gibbs free energy minimum. The impact of quantum zero-point vibrational corrections on the relative stability of these isomers is quite significant. The box-like isomers are favored in terms of electronic energy, but with the inclusion of zero-point vibrational corrections and entropic effects tree-like isomers are favored at higher temperatures. Under conditions from 0 to 298.15 K, the global minimum is predicted to be a tree-like structure with one dangling singly coordinated water molecule. Above 298.15 K, higher entropy tree-like isomers with two or more singly coordinated water molecules are favored. These assignments are generally consistent with experimental IR spectra of (H₃O⁺)(H₂O)₈ obtained at 150 K.

Journal

Computational and Theoretical Chemistry

Volume

1021

First Page

240

Last Page

248

Department

Chemistry

Link to Published Version

http://www.sciencedirect.com/science/article/pii/S2210271X13003265

Recommended Citation

Temelso, Berhane; Koddermann, Thorsten; Kirschner, Karl K.; Klein, Katurah L.; and Shields, George C.. "Structure and thermodynamics of H3O+(H2O)8 clusters: A combined molecular dynamics and quantum mechanics approach." Computational and Theoretical Chemistry (2013) : 240-248.