August 2012 - Allocations-admins - mailman3.cels.anl.gov

New LCRC report submitted for MnO2_interfaces
by support＠lcrc.anl.gov 29 Aug '12

29 Aug '12

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2012/?project=MnO2_interfac…

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New LCRC report submitted for NEAMS_Safety
by support＠lcrc.anl.gov 29 Aug '12

29 Aug '12

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2012/?project=NEAMS_Safety

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New LCRC report submitted for RadiationDamage
by support＠lcrc.anl.gov 29 Aug '12

29 Aug '12

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2012/?project=RadiationDama…

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New LCRC report submitted for SHARP_TH
by support＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2012/?project=SHARP_TH

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[LCRC Accounts] Yearly Allocation Request from Parallel_Fusion_PDEs
by accounts＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Lois Curfman McInnes Project Name: Parallel_Fusion_PDEs Division: MCS Project title: Parallel Implicit Algorithms in Edge Fusion Simulations Associated funding: DOE SciDAC program via the FACETS project (FACETS = Framework Application for Core-Edge Transport Simulations) -- prior project Other Systems: MCS workstations Science: We are developing scalable algorithms for the solution of nonlinear partial differential equations that arise in the multi-institutional SciDAC FACETS (Framework Application for Core-Edge Transport Simulations) project (PI John Cary, Tech-X Corporation). This project's aim is the construction of a multiphysics, parallel framework application, FACETS, that will enable whole-device modeling for the U.S. fusion program and ITER, the next-step fusion confinement device. FACETS will be highly flexible, through use of component technology and object oriented design, to facilitate switching among models. This will enable use of simplified models for rapid turnaround or high-fidelity models to take advantage of the largest supercomputer hardware. Project description: A critical aspect of FACETS fusion codes is the solution of time-dependent, nonlinear partial differential equations (PDEs). Solution of the nonlinear and linear algebraic systems arising from spatial and temporal discretization of these PDEs is a significant fraction of overall execution time. A primary focus of recent work with FACETS has been the introduction of robust and scalable parallel nonlinear solvers from the PETSc library into the parallel UEDGE edge transport application, with emphasis on scalable physics-based preconditioners. We are also exploring scalable solver issues for boundary turbulence modeling via BOUT++ and investigating issues in coupled multiphysics problems. Project URL: http://www.facetsproject.org Current FY Hours Used: undetermined amount New FY Requested allocation: 80000 Q1: 20000 Q2: 20000 Q3: 20000 Q4: 20000 Justification: Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Request: CosmoInfererences
by accounts＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Rahul Biswas Applicant's institution: ANL Applicant's division: HEP Project Name: CosmoInfererences Project title: Estimation of Cosmological Parameters from Large Surveys Associated funding: Other Systems: Science: The science objective of this project will be to develop codes to estimate cosmological parameters from simulations of future cosmological surveys. Constraining cosmological parameters from multiple probes simultaneously is the best way of improving our knowledge about dark energy, the cause of the late time acceleration of the universe. The focus of interest will be the supernova component of the Dark Energy Survey, but will also be working on the same problem for the Large Synoptic Survey Telescope. The project will explore different methods of performing the parameter estimation, taking into account systematics of these surveys to determine which methods afford the best recovery of information within a practical time scales. A code that prove well suited to the task, might ultimately be used for analyzing the data from these surveys. Project description: This project will largely employ Markov Chain Monte Carlo methods to sample multi-dimensional Bayesian Posterior Distributions given simulated data. While such methods are often used in ideal situations, we will need to perform these estimates accounting for experimental systematics, such as those studied by us in simulating the Dark Energy Survey (DES) Supernova (SN) survey. The goal would be to produce a code that can be added as a module to the DES analysis pipeline or used separately for the SN component of the DES. Standard publicly available open-source packages such as (cosmoMC http://cosmologist.info/cosmomc/) exist for a treatment of the problem in ideal situations and simpler models. These codes are written in Fortran90 and use a hybrid parallelization involving both MPI and OpenMP. The general concept is that model evaluations are performed using OpenMP, while several MCMC chains are simultaneously evolved using MPI in an embarrassingly parallel mode. We plan to use small numbers of nodes ~ 10 per job. We have modified these packages to allow for some of the models we need, and used them on fusion (work done on startup/ cosmology projects). We need to develop code to extend the parametrization to include parameters that would encode the experimental details. We have studied such details in a previous DES simulation study and estimated the size of constraints based on linearity. The project will require a LAPACK installation (as installed) and some analysis tools are already in MATLAB (also installed). I expect to mostly work by myself on this project, but would like to invite people working on related topics to collaborate. Accordingly, I think 5 project members would be useful to have. We might run some non-parallel jobs for the purpose of debugging and analysis stage. I expect this to be a small fraction of the time eg. less than 5 percent. Project URL: Requested allocation: 20000 Q1: 5000 Q2: 5000 Q3: 5000 Q4: 5000 Justification: The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Request: CESM
by accounts＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Robert Jacob Applicant's institution: ANL Applicant's division: MCS Project Name: CESM Project title: Community Earth System Model development Associated funding: DOE Other Systems: NCAR, ALCF, OLCF Science: Climate models treat the atmosphere and ocean as interacting fluids. They contain numerical methods to solve the basic partial differential equations which are in turn derived from the Navier-Stokes equations for a fluid on a rotating sphere. They also contain detailed parameterizations to compute the internal and external forcing terms that come from such diverse phenomena as the passage of radiation through the atmosphere, the release of latent heat by phase changes of water and the effects of friction and unresolved turbulent scales. The response of sea ice and the land surface to heating, cooling, precipitation and wind must also be modeled to close the system. The goal of most climate model development is to predict how future climate will change in response to increasing greenhouse gases. The best prediction will probably come from that model which best simulates the current climate. The most straightforward way to increase the fidelity of a climate simulation is to increase the resolution of the grid used in each model's numerical method. But this comes with a computational cost. Another way to increase the fidelity is to find more complete parameterization schemes of the forcing terms and add new parameterization schemes for any missing ones. But this also comes with a computation cost. Development of the worlds leading climate models must strike a balance between available computing power, the resolution of the grid and the completeness of the parameterizations. Project description: The Community Earth System Model (CESM) is a fully-coupled, global climate model that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. CESM is developed jointly by the National Science Foundation and the Department of Energy. CESM's atmosphere component is the Community Atmosphere Model. CAM currently supports four different numerical cores for solving the basic equations: a spectral transform method, a Semi-Lagrangian scheme, a finite-volume and a finite-element scheme. The ocean component is a finite-difference model called the Parallel Ocean Program and was developed at Los Alamos. CESM's sea ice and land surface models are each among the most complex and complete models in existence. CESM also contains models of chemical and biogeochemical processes within the main components. CESM requires Fortran90 and C compilers and the MPI library to run. We will be using time of Fusion to help build a performance model of CESM and do test developments in its software such as the Model Coupling Toolkit and Parallel I/O library. Project URL: http://www.cesm.ucar.edu Requested allocation: 8000 Q1: 2000 Q2: 2000 Q3: 2000 Q4: 2000 Justification: The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request from DFT-defects-UO2
by accounts＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Zhigang Mei Project Name: DFT-defects-UO2 Division: NE Project title: Nanoscale Modeling of Defects in Materials for Energy Applications Associated funding: ANL LDRD Other Systems: Carbon: 300000 core-hours Eddy：No time limit Science: The technological importance of actinide dioxides, AO2 (A=U, Pu or Np), largely originates from their application in nuclear reactor fuels. Today many reactor use UO2 as the primary fuel component. High-energy particle (self)irradiation in materials causes damage by creating point defects that can form defect structures such as small clusters, voids, and stacking faults, ultimately leading to material failure. The damage tolerance of a material depends not only on the number of defects created during irradiation but also on their long-time kinetic evolution. Therefore, understanding the evolution of highly interacting defects is very important. Experimentally is difficult to capture the irradiation-induced short time-scale atomistic process; computer simulations are particularly adept at capturing such dynamical process. Evaluating the concentration of point defects in actinide oxides requires a complex evaluation of the energy of formation of each defect type. The traditional mass action law is widely used to calculate the concentration of lattice defects. This formalism assumes that the defects do not interact, and that each defect occupies only one lattice site. However, complex defect structures can occupy multiple sites and the strong Coulomb and elastic repulsions may exclude other complexes from nearby sites. This is a source of great uncertainty in any statistical description, especially when the defect complexes are anisotropic. Roughly, the concentration of point defects increases with the temperature and the departure from stoichiometry, and decreases with pressure. Uranium oxide, UO2+x, which is the basis for most nuclear fuels used in Light Water Reactors, has a fluorite structure and hosts a large set of point defects to include oxygen vacancies, uranium vacancies, oxygen interstitials, as well as more complex defects such as small polarons or Willis defects. In UO2+x, uranium can exhibit valence changes from U4+ to U5+ leading to a wide range of departure from stoichiometry x, up to UO2.3. As first shown by neutron diffraction studies, this is mainly due to excess oxygen ions that are incorporated at interstitial sites and to a lesser degree to uranium vacancies. However, most current experimental and theoretical treatments of uranium oxide focus on isolated, non-interacting defects, which is consistent with small departures form stoichiometry, usually x < 0.1, and provides good descriptions of the thermochemistry of the oxide at low temperatures. The purpose of this project is to develop an understanding of defect formation in UO2+x at high defect concentrations and departures from stoichiometry, 0.1 < x < 0.3. Such an understanding will allow us to develop models of the free energy of the oxide that are valid at high temperatures, consistent with potential accident scenarios in the nuclear reactor. This study involves a comprehensive analysis of the oxide electronic and defects structure at nano-scale and using Density Functional Theory (DFT) and Ab-Initio Molecular Dynamics (AIMD). Since UO2+x is thermodynamically stable over a wide range of oxygen content in which the nature of the majority of defects may change greatly, we will examine the free energy of formation of a variety of defects types using DFT and AIMD. As opposite to previous studies, we will examine the particular cases of closely interacting defects and determine the energetics of these structures. For example, at large oxygen contents, where oxygen interstitial migration is preponderant, we will calculate the formation and activation energy for oxygen atoms diffusion as function of temperature and defect concentration. We will validate the advanced QM methods by predicting lattice constants, thermodynamics and other properties of compounds in the U-O phase diagram. Project description: To achieve the objectives of the study we will run standard density-functional theory (DFT)-based packages such as VASP and CP2K. We propose to apply these tools to model defects in non-stoichiometric uranium oxide, UO2+x (0.1<x<0.2), for the case of high defect concentrations. In addition to defect formation and migration energies, we will calculate entropic contributions to the free energy of various interacting defects to evaluate properties that are suitable for experimental validation, such as oxygen self and chemical (tracer) diffusivity in UO2+x. The LCRC’s high-performance computing cluster Fusion provides an outstanding combination of cutting-edge computational power and the efficient DFT software needed for this project. Due to the strongly correlation of U-5f electrons, more accurate methods, such as the LDA+U method and hybrid functionals, are required to overcome the limitations of conventional LDA/GGA method. These new methods require an order magnitude more of computational time to study the defects formation in UO2+x by DFT calculations. To go beyond point defects and study defect clustering and voids, we will use the AIMD capability of VASP and CP2K to study the formation and evolution of these defects in realistic time scale. With its well-developed pseudopotentials for actinide elements, VASP is extremely adept to study the static behaviors of a system with only a few hundred atoms. In the case of UO2, most of the published DFT works were limited to systems with less than two hundred atoms due to strongly correlated f-electrons. Additional complexity is the multiple metastable states accompanying DFT+U calculations for f-electrons. Approaches, such as monitoring f-electron occupation matrices and U ramping, are required to achieve the correct electronic ground state. These approaches usually require ten times of computational time than standard DFT+U calculations. This may not pose a significant problem for studying point defect formation or migration energies under the assumption of dilute defect. In additional to the formation energies of defects, we will also calculate the vibrational entropy of defect formations and effective vibrational frequencies of diffusing atoms from phonon calculations . These provide all factors entering the vacancy/interstitial-mediate self-diffusion coefficient by first-principles methods. To study the dynamics of defects in highly defected UO2, large cell with more than a thousand atoms is indispensable, which is far beyond the capability of VASP code. By exploiting linear scale method, CP2k was demonstrated to model a system with one million water molecules. Our benchmark calculations show that UO2 with a few thousand atoms can be well handled by CP2K. We will calculate the structure and thermodynamics of UO2 to establish the reliability of U GTH pseudopotential and the hybrid functional. Based on these results, we will model oxygen Frenkel pairs and Schottyky defects with the pseudopotential and functional as an additional check. Once the reference calculations are complete, we will calculate the free energy surface for the formation of the Oxygen Frenkel pair in UO2+x with metadynamics. Three person will be involved in this projected. Dr. Marius Stan is a Senior Scientist in the Nuclear Engineering Division at ANL and a Senior Fellow of the Computational Institute at University of Chciago. Dr. John Low is a Computational Scientist in Mathematics and Computer Science division at ANL. Dr. Zhi-Gang Mei is a postdoc in the Nuclear Engineering Division at ANL. Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 400000 Q1: 100000 Q2: 100000 Q3: 100000 Q4: 100000 Justification: Thank You, The LCRC Accounts System

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New LCRC report submitted for SHARP_TH
by support＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2012/?project=SHARP_TH

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New LCRC report submitted for SHARP_TH
by support＠lcrc.anl.gov 28 Aug '12

28 Aug '12

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2012/?project=SHARP_TH

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