Insight into the Binding of Argon to Cyclic Water Clusters from Symmetry-Adapted Perturbation Theory
Abstract
This work systematically examines the interactions between a single argon atom and the edges and faces of cyclic H (Formula presented.) O clusters containing three–five water molecules (Ar(H (Formula presented.) O) (Formula presented.)). Full geometry optimizations and subsequent harmonic vibrational frequency computations were performed using MP2 with a triple- (Formula presented.) correlation consistent basis set augmented with diffuse functions on the heavy atoms (cc-pVTZ for H and aug-cc-pVTZ for O and Ar; denoted as haTZ). Optimized structures and harmonic vibrational frequencies were also obtained with the two-body–many-body (2b:Mb) and three-body–many-body (3b:Mb) techniques; here, high-level CCSD(T) computations capture up through the two-body or three-body contributions from the many-body expansion, respectively, while less demanding MP2 computations recover all higher-order contributions. Five unique stationary points have been identified in which Ar binds to the cyclic water trimer, along with four for (H (Formula presented.) O) (Formula presented.) and three for (H (Formula presented.) O) (Formula presented.). To the best of our knowledge, eleven of these twelve structures have been characterized here for the first time. Ar consistently binds more strongly to the faces than the edges of the cyclic (H (Formula presented.) O) (Formula presented.) clusters, by as much as a factor of two. The 3b:Mb electronic energies computed with the haTZ basis set indicate that Ar binds to the faces of the water clusters by at least 3 kJ mol (Formula presented.) and by nearly 6 kJ mol (Formula presented.) for one Ar(H (Formula presented.) O) (Formula presented.) complex. An analysis of the interaction energies for the different binding motifs based on symmetry-adapted perturbation theory (SAPT) indicates that dispersion interactions are primarily responsible for the observed trends. The binding of a single Ar atom to a face of these cyclic water clusters can induce perturbations to the harmonic vibrational frequencies on the order of 5 cm (Formula presented.) for some hydrogen-bonded OH stretching frequencies.
Recommended Citation
C. A. Rock and G. S. Tschumper, "Insight into the Binding of Argon to Cyclic Water Clusters from Symmetry-Adapted Perturbation Theory," International Journal of Molecular Sciences, vol. 24, no. 24, article no. 17480, MDPI, Dec 2023.
The definitive version is available at https://doi.org/10.3390/ijms242417480
Department(s)
Chemistry
Publication Status
Open Access
Keywords and Phrases
argon tagging; binding energies; interaction energies; vibrational frequencies; water clusters
International Standard Serial Number (ISSN)
1422-0067; 1661-6596
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Dec 2023
PubMed ID
38139311
Comments
National Science Foundation, Grant CHE-2154403