Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Baofu Qiao Project Name: DMDOHEMA_1 Division: CSE Project title: Metal Ion Transport through Nano-Structured Lipophilic Systems: Atomistic MD Simulations Associated funding: DOE-BES Other Systems: Science: The interactions and transport mechanisms of metal ions through nano-structured soft matter systems is woefully lacking in fundamental understanding. Such systems are imported in a huge range of applications, such as: extractive separations; forming meso-porous catalytic supports; nano-particle synthesis; life-mimicking systems; etc. Understanding multi-scale structures and interactions is key to developing these important applications and is at the forefront of meso-science. However, soft-matter systems containing coordinating metal ions are notoriously difficult to probe structurally, with the best techniques being synchrotron SAXS and EXAFS giving information on the atomic metal-centric scale and supramolecular scale, respectively. Interpreting such experimental data from these complex systems can give a general idea of coordination environment and the morphology of the supramolecular solvent. However, in order to gain a truly multi-scale understanding with atomi c resolution, we must couple these experimental data with MD simulations, which can be done conveniently and powerfully by directly fitting SAXS and EXAFS data with the simulated systems. This methodology will provide a breakthrough in new fundamental insights into the structural complexity of metal ion – soft matter systems. Project description: We are currently working on two projects. In the first project, we are developing the pairwise additive CHARMM force field parameters for the trivalent metal ions. The precise understanding of the speciation behavior of metal ions depends on the accurate description of the metal ions and the interacting ligands. In contrast with the ligand, the force field parameters of most of which have been well developed, the accurate potentials for the high valent metal ions are very limited. Most of them are restricted in the polarizable potential (e.g., AMOEBA potential). These polarizable potential are computationally much more expensive. Therefore, we are aiming to develop the additive potentials for the trivalent metal ions, which are expected to be of similar accuracy with the polarizable force fields and much more computationally efficient. In specific, we are developing the additive CHARMM force field for trivalent lanthanide (Ln(III)) ions. The free energy perturbation method is employed to calculate the hydration free energy of the Ln(III) ions. The recently proposed corrections to the calculated hydration free energy are applied. Moreover, the structural features are also studied. Our preliminary results show that the obtained CHARMM fore field parameters for a variety of Ln(III) ions are capable of providing comparable accuracy with the polarizable AMOEBA force field parameters. The additive CHARMM potential is around two orders of magnitude computationally faster. We are currently writing the manuscript, and will submit it to J. Phys. Chem. Lett. for publication. In the second project, we are studying how surfactants could be employed to separate trivalent metal ions. We are currently using the anionic SDS as the amphiphilc surfactant. Preliminary simulations show that the presence of trivalent metal ions drives the SDS monomers into multilayer structure, and most of the trivalent metal ions are buried inside the multilayer structure. We are currently equilibrating the structures. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 350000 Q1: 200000 Q2: 50000 Q3: 50000 Q4: 50000 Justification: Storage requirements: 1TB storage is large enough for our project. Thank You, The LCRC Accounts System