@article {417, title = {Mechanism of Fast Proton Transport along One-Dimensional Water Chains Confined in Carbon Nanotubes}, journal = {J. Am. Chem. Soc.}, volume = {132}, year = {2010}, pages = {11395{\textendash}11397}, doi = {10.1021/ja1046704}, author = {Cao, Z. and Peng, Y. and T. Yan and Li, S. and Li, A. and G. A. Voth} } @article {428, title = {A Computer Simulation Model for Proton Transport in Liquid Imidazole}, journal = {J. Phys. Chem. A}, volume = {113}, year = {2009}, pages = {4507-4517}, doi = {10.1021/jp811156r}, author = {Chen, H. and T. Yan and G. A. Voth} } @article {503, title = {Molecular Dynamics Simulation of the Energetic Room Temperature Ionic Liquid 1-Hydroxyethyl-4Amino-1, 2, 4-Triazolium Nitrate (HEATN)}, journal = {J. Phys. Chem. B}, volume = {112}, year = {2008}, pages = {3121-3131}, doi = {10.1021/jp710653g}, author = {Jiang, W. and T. Yan and Wang, Y. and G. A. Voth} } @article {502, title = {A Multiscale Coarse-Graining Study of Liquid/Vacuum Interface of Room-Temperature Ionic Liquids with Alkyl Substituents of Different Lengths}, journal = {J. Phys. Chem. C}, volume = {112}, year = {2008}, pages = {1132-1139}, doi = {10.1021/jp077643m}, author = {Jiang, W. and Wang, Y. and T. Yan and G. A. Voth} } @article {698, title = {Understanding ionic liquids through atomistic and coarse-grained molecular dynamics simulations}, journal = {Acc Chem Res}, volume = {40}, number = {11}, year = {2007}, note = {Wang, Yanting Jiang, Wei Yan, Tianying Voth, Gregory A Research Support, Non-U.S. Gov{\textquoteright}t Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S. Review United States Accounts of chemical research Acc Chem Res. 2007 Nov;40(11):1193-9. Epub 2007 Oct 13.}, pages = {1193-9}, abstract = {

Understanding the physical properties of ionic liquids (ILs) via computer simulation is important for their potential technological applications. The goal of our IL research is to obtain a unified understanding of the properties of ILs with respect to their underlying molecular structure. From atomistic molecular dynamics simulations, the many-body electronic polarization effect was found to be important for modeling ILs, especially their dynamics. The multiscale coarse-graining methodology has also been employed to increase the simulation speed by a factor of 100 or more, thereby making it possible to study the mesoscopic behavior of ILs by computer simulations. With these simulation techniques, ILs with an amphiphilic cation were found to exhibit a spatial heterogeneity due to the aggregation of their nonpolar alkyl tails. This spatial heterogeneity is a key feature in interpreting many physical phenomena of ILs, such as their heterogeneous self-diffusion and surface layering, as well as their surfactant-like micelles formed in IL/water mixtures.

}, keywords = {Chemical Models, Chemistry, Molecular Physicochemical Phenomena Surface Properties, Physical *Computer Simulation Ionic Liquids/*chemistry *Models}, doi = {10.1021/ar700160p}, author = {Wang, Y. and Jiang, W. and T. Yan and G. A. Voth} } @article {697, title = {Multiscale Coarse-Graining of Ionic Liquids}, journal = {J Phys Chem B}, volume = {110}, number = {8}, year = {2006}, note = {Wang, Yanting Izvekov, Sergei Yan, Tianying Voth, Gregory A Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S. United States The journal of physical chemistry. B J Phys Chem B. 2006 Mar 2;110(8):3564-75.}, pages = {3564-75}, abstract = {

A recently developed multiscale coarse-graining (MS-CG) approach for obtaining coarse-grained force fields from fully atomistic molecular dynamics simulation is applied to the challenging case of the EMIM+NO3- ionic liquid. The force-matching in the MS-CG methodology is accomplished with an explicit separation of bonded and nonbonded forces. While the nonbonded forces are adopted from this force-matching approach, the bonded forces are obtained from fitting the statistical configurational data from the atomistic simulations. The many-body electronic polarizability is also successfully broken into effective pair interactions. With a virial constraint fixing the system pressure, the MS-CG models rebuild satisfactory structural and thermodynamic properties for different temperatures. The MS-CG model developed from a modest atomistic simulation is therefore suitable for simulating much larger systems, because the coarse-grained models show significant time integration efficiency. This approach is expected to be general for coarse-graining other ionic liquids, as well as many other liquid-state systems. The limitations of the present coarse-graining procedure are also discussed.

}, keywords = {*Algorithms Ionic Liquids/*chemistry Temperature}, doi = {10.1021/jp0548220}, author = {Wang, Y. and Izvekov, S. and T. Yan and G. A. Voth} } @article {720, title = {Structure of the Liquid-Vacuum Interface of Room-Temperature Ionic Liquids: A Molecular Dynamics Study}, journal = {J Phys Chem B}, volume = {110}, number = {4}, year = {2006}, note = {Yan, Tianying Li, Shu Jiang, Wei Gao, Xueping Xiang, Bing Voth, Gregory A United States The journal of physical chemistry. B J Phys Chem B. 2006 Feb 2;110(4):1800-6.}, pages = {1800-6}, abstract = {

Molecular dynamics simulations for the liquid-vacuum interface of the ionic liquid 1-ethyl-3-methylimidazolium nitrate (EMIM+/NO3-) were performed for both electronically polarizable and nonpolarizable potential energy surfaces. The interfacial structural properties, such as the oscillation in the number density profile, the orientational ordering, and the local clustering in the interfacial region, were calculated. The simulations with both the polarizable and nonpolarizable model demonstrate the existence of an inhomogeneous interfacial structure normal to the surface layer. It was found for both models that the ethyl tail group on EMIM+ is likely to protrude outward from the surface. In the outmost surface layer, the cation is likely to lie on the surface with the imidazolium ring parallel to the interface, while there is a second region with enhanced density from that in the bulk where the cation preferably slants with the imidazolium ring tending to be perpendicular to the surface. The results also reveal that the electronic polarization effect is important for the ionic liquid interface. It is found that the cation is likely to be segregated at the ionic liquid surface for the polarizable model, while for the nonpolarizable model, the anion is found to be more likely to exhibit such behavior. The surface tension of the polarizable model (58.5 +/- 0.5 mN/m) is much smaller than that of the nonpolarizable model (82.7 +/- 0.6 mN/m), in better agreement with extrapolated experimental measurements on similar ionic liquid systems.

}, doi = {10.1021/jp055890p}, author = {T. Yan and Li, S. and Jiang, W. and Gao, X. and Xiang, B. and G. A. Voth} } @article {719, title = {Molecular Dynamics Simulation of Ionic Liquids: The Effect of Electronic Polarizability}, journal = {J. Phys. Chem. B}, volume = {108}, year = {2004}, pages = {11877-11881}, doi = {10.1021/jp047619y}, author = {T. Yan and C. J. Burnham and Popolo, M. G. Del and G. A. Voth} }