Revisit the landscape of protonated water clusters H+(H2O)n with n = 10–17: An ab initio global search

作者：Ruili Shi, Keyao Li, Yan Su, Lingli Tang, Xiaoming Huang, Linwei Sai, Jijun Zhao · 发表于：The Journal of Chemical Physics · 年份：2018 · DOI：10.1063/1.5026383 · 被引用次数：18 · 研究领域：Advanced Chemical Physics Studies、Spectroscopy and Quantum Chemical Studies、Atmospheric Ozone and Climate

Using a genetic algorithm incorporated with density functional theory, we explore the ground state structures of protonated water clusters H+(H2O)n with n = 10–17. Then we re-optimize the isomers at B97-D/aug-cc-pVDZ level of theory. The extra proton connects with a H2O molecule to form a H3O+ ion in all H+(H2O)10-17 clusters. The lowest-energy structures adopt a monocage form at n = 10–16 and core-shell structure at n = 17 based on the MP2/aug-cc-pVTZ//B97-D/aug-cc-pVDZ+ZPE single-point-energy calculation. Using second-order vibrational perturbation theory, we further calculate the infrared spectra with anharmonic correction for the ground state structures of H+(H2O)10-17 clusters at the PBE0/aug-cc-pVDZ level. The anharmonic correction to the spectra is crucial since it reproduces the experimental results quite well. The extra proton weakens the O–H bond strength in the H3O+ ion since the Wiberg bond order of the O–H bond in the H3O+ ion is smaller than that in H2O molecules, which causes a red shift of the O–H stretching mode in the H3O+ ion.