Dynamics and structural changes of small water clusters on ionization

Abstract

Despite utmost importance in understanding water ionization process, reliable theoretical results of structural changes and molecular dynamics (MD) of water clusters on ionization have hardly been reported yet. Here, we investigate the water cations [(H2O)(n = 2-6)(+)] with density functional theory (DFT), Möller-Plesset second-order perturbation theory (MP2), and coupled cluster theory with single, double, and perturbative triple excitations [CCSD(T)]. The complete basis set limits of interaction energies at the CCSD(T) level are reported, and the geometrical structures, electronic properties, and infrared spectra are investigated. The characteristics of structures and spectra of the water cluster cations reflect the formation of the hydronium cation moiety (H3O(+)) and the hydroxyl radical. Although most density functionals fail to predict reasonable energetics of the water cations, some functionals are found to be reliable, in reasonable agreement with high-level ab initio results. To understand the ionization process of water clusters, DFT- and MP2-based Born-Oppenheimer MD (BOMD) simulations are performed on ionization. On ionization, the water clusters tend to have an Eigen-like form with the hydronium cation instead of a Zundel-like form, based on reliable BOMD simulations. For the vertically ionized water hexamer, the relatively stable (H2O)5(+) (5sL4A) cluster tends to form with a detached water molecule (H2O).

Structural exploration and properties of (H2O)4+ cluster via ab initi

“…The relative energies of these isomers are also included for quantitative comparison. The obtained AIP for W 1 without ZPVE correction is 9.89 eV, which coincides with the reported value [46].…”

“…The detailed schemes of the hemi-bonded type are difficult to give a good account, so the relevant descriptions are omitted. Lee and Kim[46] deduced and ) and 4nR4 (neutral water molecule type). The four isomers reported by Do and Besley[47] are also found by us.Fig.…”

Triggering comprehensive enhancement in oxygen evolution reaction by using newly created solvent

“…Water molecules exist in the form of water clusters in bulk water due to strong HB interactions. It was reported that the interaction energy of H 3 O + –OH − is 46.9 kJ mol −1 , and it increases approximately 2.5-times when H 3 O + associates with an additional four water molecules24. Based on the two features, the combination of using sAuNT water with weak HBs in OER is proposed (Fig.…”

Medicamentos homeopáticos e o paradigma da evidência científica

“…Magnética Nuclear (RMN) onde gases dissolvidos na água parecem afetar a rede de ligações de hidrogênio e modificar a estrutura das nanobolhas ou das nanocavidades dos clatratos 34 . Além disso, a dinâmica de pequenos clusters de água é também marcadamente afetada pelo processo de ionização 20,35 . Neste contexto, tem sido sugerida a participação da sílica na formação de aglomerados de água; esta seria liberada a partir dos recipientes de vidro, utilizados normalmente na preparação dos medicamentos homeopáticos 36 .…”