Hello, A change in allocation has been requested: Requester: kclau (Kah Chun Lau) Project: Li_air_battery Title: Computational studies of Li-Air battery components Description: In the coming fiscal year (FY2013), we will complete our current on-going work and explore different systems in Li-air batteries based on experimental input from our colleagues at ANL. To complete the current ongoing study (i.e. ionic transport, ether-based solvents with different Li-salts), our experience indicates that 100, 000 hours is required. For our new study at FY2013, the computational methods will involve largely AIMD (CPMD, VASP) and DFT method (Gaussian09, VASP). For Gaussian09, the DFT calculation scales well up to 8 processors and for 4-6 nodes is the optimal number of nodes for geometry optimization for system size below 100 atoms. We will likely require about 100,000 core hours to study the stability and reaction paths of new longer ether-based (i.e. with spacer and dopants) and DMSO solvents against different Li salts in gas phase and solution phase. To extend our previous DFT study on Li2O2 (crystalline bulk, surfaces and clusters) system, mo re extensive solid phases of Li2O2/LiO2 and Li2O/Li2O2/LiO2 hetero-interfaces (with and without impurity/dopants), together with the equation of states, mechanical, electronic and thermodynamic properties will be explored using DFT planewave VASP code. The VASP code is well-parallelized for 64-72 cores for 100-200 atoms system for a finite k-point calculation. For a single Γ-point calculation with a total atom ~ 300 atoms, a parallel efficiency of ~ 60% -75% can be achieved using 256 cores. Thus to explore a moderately large systems (~ 100-200 atoms), 200 000 core-hour is needed to perform the tasks. In addition, the larger system of combined electrolyte/electrode (electrolyte/Li2O2/carbon with and without metal catalyst) (~ 400 atoms) interfaces will be computed using CPMD and VASP code. We will explore the chemical reactions (i.e. rare events) based on AIMD method. For system involves metal-catalyst (e.g. Au) that involves d-orbital electrons, the blue-moon approach based on VASP code will be used. For a system without metal catalyst, the metadynamics approach implemented in CPMD code will be used. In order to have a reliable statistics and long enough simulation time, we will require about 400, 000 core hours to complete these computational intensive simulations. Current: undetermined amount Justification: For the details and evidence how to use the hours effectively, please see the project description and project report (FY2012). Further details of the scaling and the performance of the codes can be found as follows: (1) VASP: http://cms.mpi.univie.ac.at/vasp/vasp/Performance_parallel_code_on_various_m... (2) CPMD: http://cpmd.org/documentation (3) Gaussian09: http://www.gaussian.com/g_prod/g09_glance.htm Requested: 200000 A specific reason has been given: Need to finish up on-going calculations for paper write-up This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System