The Spectroscopic Features of Ionized Water Medium: Theoretical Characterization and Implication Using (H2O)n+, n=3–4, Cluster Model

摘要: A model using (H2O)n+, n=3–4, clusters was adopted to study the spectroscopic features of ionized water medium. The finite were characterized a systematic searching algorithm locate stable minimum structures. electronic transition structures calculated Symmetry Adapted Cluster/Configuration Interaction (SAC-CI) and Time-Dependent Density Functional Theory (TDDFT) approaches. new type structure – SolCat, cationic monomer being directly solvated by two proton-acceptor solvent molecules, identified in addition proton transfer (PT) hemibonding (Hm) isomers. CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVDZ characterize n=2–4, clusters, this theory level provided converged energetics for (H2O)2+ showed consistent results as early EOM-IP-CC(2,3)//EOM-IP-CCSD calculations reported Pieniazek et al. [J. Phys. Chem. A, 112, 6159–6170 (2008)]. For describing larger size BH&HLYP BNL functionals recommended economical geometry sampling. predicted functional gave best vertical excitation energy with respect SAC-CI method. Taking into account population probability oscillator strength, transient but spectroscopically-sensitive Hm SolCat species could not be neglected at high temperature condition.