Hello, A change in allocation has been requested: Requester: leicheng (Lei Cheng) Project: ElectrolyteRedoxFlow Title: discoveries of electrolyte for redox flow batteries Description: In this renewal work, we will continue focusing on fundamental properties of transition metal complexes as redox active molecules for non-aqueous redox flow battery application. In collaboration with experimental group (Prof. Thompson, University of Michigan), we have previously studied redox windows of some novel compounds. We now study the solubilities of these compounds in non-aqueous solutions as the capacity of this type of battery is directly proportional to redox window and concentration of active compound in solution. Insight gained from these studies will greatly guide design and synthesis of the compounds experimentally. In previously proposed work, we have successfully determined the B3LYP/6-31+G* and BP86/6-31+G* combinations as proper computational treatments for these system. The same methods will be used to calculate solvation energies of Cr, V, Mn and Fe based novel compounds. These energies will be calculated using both implicit continuum models such as PCM, CPCM and SMD methods, as well as explicit model with actual solvent molecules added to the quantum calculations. These solvation energies will then be compared with experimentally measured solubilities of the compounds to determine correlation between the two. Calculations with explicit solvent molecules will also be performed to further validate accuracy of the implicit model calculations as well as provide more insights on coordination details of the metal complexes by solvent molecules. Recently, interesting solubility trends of metal complexes in different binary organic solvents have been observed experimentally (private com munication). We will also guide our research efforts towards providing physical understandings of the observed experimental results. All calculations will be performed using Gaussian and NWCHEM. These two code packages are both considered very efficient and reliable for quantum chemistry calculations. Gaussian is not very scalable but it provides really robust geometry optimizer and the G3/G4 methods are built-in. NWChem is very scalable especially for higher level calculations such as coupled cluster methods and perturbation theories. After interesting molecule candidates and appropriate calculation methods are identified, derivatives of these molecules will be subject to high-throughput screening. The high-throughput screening will be performed using NERSC supercomputers. Current: undetermined amount Justification: The size of molecules we propose to study is very typical for the two computational software (Gaussian and NWChem) so they scale reasonably well for most DFT calculation. The higher level calculations will consume more memory as well as computational time. The NWChem code uses a globally-shared memory system, therefore one can request and utilize more memory through node parallelization. Requested: 50000 A specific reason has been given: We have used up the computing time allocated because the systems (metal organic complexes) of interest are a lot harder to converge than expected due to the presence of transition metals with different possible charge and multiplicity states. In addition, our experimental collaborators have discovered some more interesting systems with different metal centers that we are interested in investigating computationally. We are preparing a manuscript based on the work conducted under this proposal. These additional allocation will allow us to finish the extra computations needed. I really appreciate your consideration! Sincerely, Lei Cheng This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System