Structure and dynamics of hydrated ions—new insights through quantum mechanical simulations

A Combined QM/MM Molecular Dynamics Simulations Study of Nitrate Anion (NO3-) in Aqueous Solution

“…The B3LYP method proved inferior in this case, but it was also employed in this work in order to test its adequacy for the description of hydrated anions, as several cases have shown that the DFT methods can give poor results for hydrated cations. 5,24,25 It should be realized that while the HF scheme could produce an error due to the neglect of electron correlation effects, the DFT methods, although including such effects to a certain (uncontrollable) extent, are often found to overestimate the correlation energy. [23][24][25][26] On the other hand, a comparison of the HF calculations with the DFT results could be helpful to give a qualitative estimate of a possible influence of correlation effects.…”

“…[3][4][5] Considering the structural feature of ions solvated in aqueous solution, cations usually have simple solvation geometries due to their relatively large binding energies between the cation and water. Unlike cations, anion solvation is more complicated since most of the anion-water interactions are generally weaker than those of cations and energetically comparable with the water-water interactions.…”

MD Simulation of the Ion Solvation in Methanol-Water Mixtures

“…This model has been frequently employed to simulate aqueous solutions of electrolytes, both in classical (Dietz et al, 1982;Jancso et al 1985;Probst et al, 1985, Probst et al, 1991Hawlicka & Swiatla-Wojcik, 1995, Lavenstein et al 2000Ibuki & Bopp, 2009) and in QM/MM MD (Tongraar & Rode, 2003, Rode et al, 2004, Öhrn & Karlström, 2004Tongraar & Rode, 2005, Payaka et al, 2009Tongraar et al, 2010) simulations. The BJH potential is appropriate to simulate the methanol-water mixtures, because it is fully consistent with the PHH flexible model (Palinkas et al 1987) of the methanol molecule.…”

“…Such approach includes many-body interactions between particles within the solvation shell. QM/MM MD simulations were carried out for aqueous solutions of various ions (Tongraar & Rode, 2003, Rode et al, 2004, Öhrn & Karlström, 2004Tongraar & Rode, 2005, Payaka et al, 2009Tongraar et al, 2010). Their results evidenced a significant role of the many-body interactions on structural and dynamical properties of the hydrated ions.…”

Simulations of Liquid Ammonia Based on the Combined Quantum Mechanical/Molecular Mechanical (QM/MM) Approach

“…It provides more informative insights into the structure and dynamics of various condensed-phase systems, in particular ionic solutions. [25][26][27][28][29][30][31][32][33][34] Very recently, a QM/MM simulation has been performed for pure water 35 that compares the performance of the second-order Møller-Plesset perturbation theory (MP2), the Hartree-Fock (HF) and the density functional theory (DFT) methods. It has been demonstrated that the HF-and MP2-based simulations provided detailed information on pure water in which are in good agreement with most recent experimental data.…”