Towards complete assignment of the infrared spectrum of the protonated water cluster H+(H2O)21

• DOI: 10.1038/s41467-021-26284-x
• Publication Date: 2021-10-22T10:09:32Z
• Authors: Jinfeng Liu; Jinrong Yang; Xiao Cheng Zeng; Sotiris S. Xantheas; Kiyoshi Yagi; Xiao He
• Keywords: Water cluster; Overtone; Cooperativity

Abstract The spectroscopic features of protonated water species in dilute acid solutions have been long sought after for understanding the microscopic behavior proton with gas-phase clusters H + (H 2 O) n extensively studied as bottom-up model systems. We present a new protocol calculation infrared (IR) spectra complex systems, which combines fragment-based Coupled Cluster method and anharmonic vibrational quasi-degenerate perturbation theory, demonstrate its accuracy towards complete accurate assignment IR spectrum 21 cluster. site-specific spectral signatures reveal two distinct structures internal surface four-coordinated molecules, are ice-like liquid-like, respectively. effect inter-molecular interaction between molecules is addressed, resonance found O-H stretching fundamental bending overtone nearest neighboring molecule. revelation signature excess offers deeper insight into nature charge accommodation extended hydrogen-bonding network underpinning this aqueous