Liu, Jing-MinJing-MinLiuHuang, Qian-RuiQian-RuiHuangCHIH-KAI LINKuo, Jer-LaiJer-LaiKuo2025-06-302025-06-302025https://scholars.lib.ntu.edu.tw/handle/123456789/730376The possible existence of a hemi-bond in the cationic complex of water and Ar has been actively debated in the literature. We simulated vibrational spectra of low-energy conformers of H2O+-Arn (n = 1, 2) in the mid- and near-infrared regions based on ab initio anharmonic algorithms with potential energy at CCSD/aug-cc-pVTZ quality. Decent agreements between experimental data and spectra simulated with four types of normal modes, intermolecular translation, H-O-H bending, and O-H stretching, validate our computational algorithms. By cross-examination of the available experimental data and our simulations, we believe that both the hydrogen-bond and hemi-bond conformers of H2O+-Ar2 should coexist under the experimental conditions. Our simulated spectra of hemi-bond conformers of H2O+-Ar2 further suggest that spectral features in the under-explored part of the near-infrared region may provide additional spectral features to double check the existence of the hemi-bond conformer.enjournal article10.1039/d5cp00054h