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[LCRC Accounts] Project Request: MEA
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

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: hakim iddir Applicant's institution: ANL Applicant's division: MSD Project Name: MEA Project title: Modeling Electrolyte Additives Associated funding: EERE Other Systems: Science: Nickel-rich layered oxide cathode materials have seen widespread deployment due to their high gravimetric capacity and high average discharge voltage. However, achieving this high capacity requires charging voltages above the potential at which the electrolytes decompose at the cathode surface (>4.5 V vs. Li/Li+), which leads to impedance rise and capacity loss. One strategy to stabilize this interface is by the use of electrolyte additives that, in small amounts, can change the chemical interactions at the interface and favorably affect the surface stability. Knowledge of the cathode-electrolyte interactions is necessary to better understand the degradation and action mechanism of such additives. Project description: Within the High Energy High Voltage (HEHV) project we have undertaken a multi-pronged approach to understand the chemical reaction mechanisms of a family of structurally related phosphates and phosphites on the surface of a charged LiNi0.5Mn0.3Co0.2 cathodes, as well as their effect on cell performance. Our approach includes electrochemical and mechanistic evaluation, characterization, and theoretical simulations with phosphorus-based additives. We will use Density Functional Theory (DFT) in order to elucidate the mechanism of reaction of electrolyte molecules on Li(Ni1-x-yMnxCoy)O2 (NMC) surfaces. We have determined so far the first oxidation steps of select alkyl carbonate electrolyte species. We also used Ab Initio Molecular Dynamics (AIMD) to explore possible adsorption configurations of several phosphite and phosphate molecules on the most reactive NMC surfaces; and computed the relative stability of different additives and their derivatives on NMC surfaces. At high states of charge, we found different reactive pathways depending on additive characteristics such as the size of the functional groups in the phosphite molecule and the degree of decomposition of such species.1,2 These studies provide some insights into the mechanism of phosphite additive oxidation on the cathode. We plan on continuing this study using several new functional group and different NMC facets. In this project we propose to check several combinations of alkane groups and silyl groups and also transesterification products of the additives with the alkyl-carbonates solvent molecules. This account for at least 12 different additive molecules. We estimate at least four reaction steps for each possible pathway. Considering two different pathways on two different surfaces, we have to compute 192 adsorption energies. Since each surface slab have about 250 atoms, we will need at least 2000 computer hours per calculation. Several initial molecule/surface configurations are needed to determine the lowest energy state. This would account for 600000 computer hours. We also will compute the energy barriers for the most thermodynamic favorable transformations in the surface of the cathode. We will use the Nudged Elastic Band (NEB) method to accomplish these calculations. These calculations would require approximately 200000 computer hours. A total of 800000 computer hours would b e needed to accomplish the proposed project. References (1) Peebles, C.; Sahore, R.; Gilbert, J. A.; Garcia, J. C.; Tornheim, A.; Bareño, J.; Iddir, H.; Liao, C.; Abraham, D. P. Tris(Trimethylsilyl) Phosphite (TMSPi) and Triethyl Phosphite (TEPi) as Electrolyte Additives for Lithium Ion Batteries: Mechanistic Insights into Differences during LiNi0.5Mn0.3Co0.2O2-Graphite Full Cell Cycling. J. Electrochem. Soc. 2017, 164 (7), A1579–A1586. (2) Tornheim, A.; Peebles, C.; Gilbert, J. A.; Sahore, R.; Garcia, J. C.; Bareño, J.; Iddir, H.; Liao, C.; Abraham, D. P. Evaluating Electrolyte Additives for Lithium-Ion Cells: A New Figure of Merit Approach. J. Power Sources 2017, 365, 201–209. Industry partnership: Project URL: Requested allocation: 800000 Q1: 200000 Q2: 200000 Q3: 200000 Q4: 200000 Justification: In this project we propose to check several combinations of alkane groups and silyl groups and also transesterification products of the additives with the alkyl-carbonates solvent molecules. This account for at least 12 different additive molecules. We estimate at least four reaction steps for each possible pathway. Considering two different pathways on two different surfaces, we have to compute 192 adsorption energies. Since each surface slab have about 250 atoms, we will need at least 2000 computer hours per calculation. Several initial molecule/surface configurations are needed to determine the lowest energy state. This would account for 600000 computer hours. We also will compute the energy barriers for the most thermodynamic favorable transformations in the surface of the cathode. We will use the Nudged Elastic Band (NEB) method to accomplish these calculations. These calculations would require approximately 200000 computer hours. A total of 800 000 computer hours would be needed to accomplish the proposed project. Storage requirements: 1 TB 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 for ReNiO3
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Peter Zapol Project Name: ReNiO3 Division: MSD Project title: Structural Evolution of rare earth nickelates under high pressure conditions Associated funding: BES Other Systems: Science: Rare earth nickelates with the specific formula ReNiO3, where Re is a rare earth metal, exhibits exotic physical properties and have attracted a lot of research interest. It shows a sharp insulator to metal transition, which is not well understood. Further to this, in the insulating phase Ni exhibits a complex antiferromagnetic ordering below the Néel temperature and the oxygen octahedra around Ni positions are significantly distorted, which leads to the manifestation of Jahn-Teller effect. The distinct Ni-O bond distances observed for Ni atoms also suggest the presence of a charge disproportionation effect. Computational efforts are needed to gain insight into different mechanisms of structural and electronic transitions with applied pressure. In this study, we plan to address how the structure and electronic properties of ReNiO3 change under high pressure effects. Using density functional theory and Green function calculations, we will calculate structure and spectra to compare to x-ray experiments done at the APS. We will focus on interpretation of the results that can help to better understand metal-insulator transition. This study will provide fundamental information on electronic properties of the important class of complex oxides and guide the ongoing experimental efforts at the APS. Project description: We were able to carry out structure optimizations of SmNiO3 (~80 atoms) with different magnetic configurations and under different pressures and performed the atomic relaxations within the unit cells. using (2 x 1x 2) bulk unit cells and GGA+U density functional. We intend to carry out the density functional theory (DFT) calculations using the VASP package. Periodic boundary condition (PBC) will be imposed in order to maintain periodicity of the solid support. By comparing different magnetic ordering energies we found configuration corresponding to the ground state energy. Now we plan to extend these studies to ReNiO3 materials using HSE functional. Since ReNiO3 are strongly correlated complex oxides we will perform density functional theory (DFT) calculations using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional (~80 atoms contain 16 Ni with different spin configurations) . We will perform most of these calculations using Broadwell nodes, but we will explore KNL nodes for the HSE calculations as well. Once we explored SmNiO3 is found we will go on to address the structural dependence of other ReNiO3 under high pressures. Our estimates are that energy optimization of ReNiO3 (~80 atoms contain 16 Ni with different spin configurations) using HSE takes approximately 414000 CPU hours (36*4*48 for roughly 60 of such calculations). For pressure calculations, this takes roughly 553000 CPU hours (36*4*48 for 80 of these calculations). To investigate metal-insulator transition we plan to run additional HSE calculations for the density of state (DOS) at the ambient pressures of 0 GPa to 3.4 GPa. So our total request is 414000+553000=967000 core hours. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 960000 Q1: 240000 Q2: 240000 Q3: 240000 Q4: 240000 Justification: we have tested vasp on bebop and we can run calculations at 4 or 8 nodes (144 or 288 cores). Storage requirements: 1 Tb is sufficient Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for chemexp
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Peter Zapol Project Name: chemexp Division: MSD Project title: Chemical Expansion in Perovskites Associated funding: DOE BES Other Systems: none Science: The solid oxide fuel cell (SOFC) presents a highly attractive energy conversion option besides the conventional energies as a clean and efficient energy conversion technology. However, the high operating temperature limits its commercial applications. The LaxSr1-xCoyFe1-yO3-delta (LSCF) displaying mixed ionic electronic conductivity serves as a promising cathode material for intermediate-temperature SOFCs. For the LSCF perovskite materials, the oxygen stoichiometry plays a critical role in the materials performance characteristics. Recently experiments showed that the oxygen stoichiometry can be investigated usingg x-rays under applied electrical potentials across the LSCF/YSZ (yttria-stabilized zirconia) heterostructures. The change in the oxygen vacancy concentration leads to a significant dilation or contraction of the lattice known as chemical expansion, which gives a way to investigate thermodynamic and kinetic effects arising from oxygen reduction reaction. U nderstanding the in-situ lattice changes with the bias voltage is critical because it sheds light on operation of the SOFC at different potantials and in different chemical environments. Collaborating with the experimentalists at Argonne, we will carry out a series of researches to compare and explain the experiment results. Project description: project description Previously we have performed calculations using density functional theory to explore the lattice changes with the oxygen stoichiometry in the bulk and on the surface of LSCF. Next, we will explore thin films and the oxygen vacancy migration across the LSCF/YSZ interface and in the thin film LSCF in the presence of ambient air species. The projector augmented plane-wave method as implemented in the Vienna ab initio simulation package (VASP) will be employed to find the optimized structures of surface species interacting with different oxygen vacancy configurations. VASP is a well validated code which is installed at LCRC and is widely used for this type of calculations with good performance. We have performed a number of tests on the BEBOP with Broadwell nodes. We will use 4 Broadwell nodes (144 cores) per calculation. The climbing image nudged elastic band method (NEB) will be used to study the oxygen vacancy migration and surface reactions of ambient species. We plan to d o calculations of different oxygen vacancy concentrations for surface cells corresponding to deviation from formal oxygen stoichiometry of 3 by 0.125, 0.25, 0.375, 0.5. For each configuration, we need several calculations to find the optimized ionic positions at fixed in-plane lattice constant. In each calculation, we need about 10 hours of run time when using 4 nodes. For the surface reactions, each NEB calculation is about 30 hours using 144 cores. We need to calculate about 5 NEB points, 4 pathways for the 4 different oxygen vacancy concentrations and 2 different surface species. Therefore, expected time estimate for surface structural optimizations is (36 cores/node * 4 nodes * 10 hours of run time * 16 different runs) 23,000 core-hours and for NEB calculations is (36 cores/node * 4 nodes * 20 hours of run time * 200 different runs)=460,000 core-hours. The total time requested is 480,000 core hours. There will be two to three members in the project Industry partnership: none Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 480000 Q1: 120000 Q2: 120000 Q3: 120000 Q4: 120000 Justification: Storage requirements: default storage allocation is sufficient Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Request: NanoDet
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

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: Spencer Hills Applicant's institution: ANL Applicant's division: NST Project Name: NanoDet Project title: Combined Experimental-Computational Nanocluster Structural Determination Associated funding: LDRD Other Systems: Carbon at Center for Nanoscale Materials (620,000 hours) Cori at NERSC (260,000 hours) Science: Determining the atomistic structures of nanoscale systems such as nanoclusters is a fundamental problem in nanoscience. The knowledge of these structures reveals important information about the functionality of these systems, allowing them to be used for applications such as opto-electrics and catalysis. Although there are both experimental and computational methods to determine these nanoscale structures, they both possess limitations which demonstrate the difficulty of nanoscale structural determination. With experimental data, such as pair distribution function (PDF), multiple possible structures may correspond to the same data, but not all such structures are physically plausible. In computational work, theoretical calculations of the system may result in several structures with similar energies, as well as requiring numerous configurations of the system to be tested. Using a modular computational framework currently being developed at the Theory and Modeling group of the Center for Nanoscale Materials, we expect to overcome the limitations of either data type by combining both experimental and computational data. This will allow us to efficiently sample the possible configurations of our test systems and determine the atomistic structures of various systems, from nanoclusters to grain-boundaries and PV interfaces. Project description: We will use the modular global optimization code which is being developed in Python by current members of our group (Spencer Hills, Fatih Sen, Grace Lu, Eric Schwenker, Maria Chan). This code can perform several types of global optimization, including GA for periodic and non-periodic systems. We plan to consider several systems within the project: 1. The structure of transition metal nanoclusters, such as gold nanoclusters, which are useful for catalytic processes. These structures have been studied extensively by our group with plane-wave DFT calculations (VASP) using a genetic algorithm, which found a broad range of structures that exhibit very large structural differences with only small energy differences. These systems represent a perfect test case for the global optimization code that we are developing, since they have diverse geometries with minimal energy differences, which allows us to test the ability of the code to distinguish between similar energy structures. We will perform global optimization of the structures using combined experimental-computational optimization and only computational optimization to compare the efficiency of each method. We will use simulated pair distribution function (PDF) data from DiffPy for the experimental data and DFT calculations using VASP for computational data. For each glo bal optimization, in this case genetic algorithm, we need to perform DFT calculations for 1000 structures. Assuming 15 minutes for each structure to relax on 64 cores, 16,000 hours are required per optimization. In order to produce meaningful comparison between the two sets of optimizations, we will run 20 optimizations (10 combined experimental-computational, 10 computational only), bringing the total requested time to 320,000 hours (0.25 hours x 64 cores x 1000 structures x 20 runs). 2. The structure of CdTe grain-boundaries from STEM images. We will consider large scale experimental-computational optimization with a periodic GA using LAMMPS and a STEM image similarity code, developed by a member of our group, to optimize the energy and comparison to experimental data. We also will optimize smaller scale grain-boundaries using the DFT code VASP and the same STEM image similarity code. Since the exact number of atoms in the grain-boundary is undetermined, we will run 20 different calculations with varying ratios of Cd:Te. Each geometry optimization will take 30 hours. These calculations have a two-fold importance: to develop our GA code to treat periodic boundary conditions, and to determine the structure of experimental grain-boundaries. (2 calculation types x 20 calculations x 30 hours x 256 core hours=307,200 hours) 3. The structural optimization of solid interfaces in Li-ion batteries and Si photovoltaics. These structures will be determined using the same GA code with periodic boundary conditions as in #2 above, and using DFT calculations with VASP. Running 10 optimizations for each of 5 interfaces, we expect each run to run to require 15 hours on 256 cores. (2 materials x 50 calculations x 15 hours x 256 core hours=384,000 hours) The total production run hours above add up to 1,011,200 hours. We estimate using roughly an additional 190,000 core hours for debugging, benchmarking and convergence tests. We require the following packages to be installed: • Anaconda Python 2.7 • VASP 5.4.4 Industry partnership: N/A Project URL: Requested allocation: 1200000 Q1: 300000 Q2: 300000 Q3: 300000 Q4: 300000 Justification: All systems considered have been tested on KNL nodes on Cori at NERSC. As such, the required time for each previous result is relevant, since both Cori and Bebop use KNL nodes. The DFT calculations mentioned above have been benchmarked on Knight’s Landing nodes (KNL). The parallel performance of our genetic algorithm code has been tested on Au nanocluster test cases. When 1 KNL node is used, performing 4 VASP calculations, each model takes 41.76 seconds. If only one VASP calculation is run on 1 KNL node, it takes 29.69 seconds. This means, that by running 4 VASP calculations simultaneously on a KNL node, about 3x the total number of VASP calculations can be run per node-hour compared to only 1 calculation at a time. For the second and third systems considered, previous results from Cori KNL VASP calculations show that there is a weak-scaling parallel performance. When 4 KNL nodes are used to run VASP calculations there is a parallel efficiency of 106% when compared to a calculation on 2 KNL nodes. Storage requirements: 1 TB 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: Thermal_transport
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

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: Yi Xia Applicant's institution: ANL Applicant's division: NST Project Name: Thermal_transport Project title: First-principles modeling of high-order phonon-phonon interactions in MCl (M=Li, Na, K, Rb) and PbX (X=S, Se, Te): method development and validation Associated funding: Midwest Integrated Center for Computational Materials (MICCoM) at DOE's Argonne National Laboratory Other Systems: National Energy Research Scientific Computing Center (NERSC): 170,000 core hours Science: Lattice thermal conductivity (LTC) is an important parameter of a material, which can be engineered to enhance or inhibit heat transfer to improve thermal efficiency and energy sustainability. Low LTC is required for thermoelectric conversion and thermal barrier coatings so as to increase thermoelectric energy conversion efficiency and reduce heat dissipation [1-3]. Developing reliable method for predicting and validating materials’ thermal transport properties is one of the focuses of the Midwest Integrated Center for Computational Materials (MICCoM), which develops and disseminates interoperable open source software, data and validation procedures to enable better design of functional materials [4]. Currently, two popular methods used to compute lattice thermal conductivities of bulk materials are based on performing molecular dynamics (MD) and solving phonon Boltzmann transport (BTE) equation. The former is applicable for both bulk and nanostructured materials, and includes anharmonicity to infinite orders. However, obtaining accurate and efficient classical force fields, or developing efficient approaches for time sampling from ab initio MD remain key challenges. In addition, quantum statistics at low temperature remain unaccounted for in classical or ab initio MD [5]. Phonon BTE is known for fully including quantum effect, less size dependence compared with MD and accuracy [6]. However, BTE-based methods have yet to be improved to take into account high-order PPIs beyond three-phonon process that lead to more accurate phonon mode (quasiparticle) frequency and lifetime. In this project, we will mainly focus on developing and validating new methods to account for high-order PPIs within the phonon BTE framework. To correctly reproduce the phonon frequency due to high-order PPIs, we will extract renormalized interatomic force constants (IFCs) at finite temperature utilizing a recently developed method called compressive sensing lattice dynamics (CSLD) [7]. To obtain accurate phonon mode lifetime, we will consider both three- and four-phonon scattering processes [8]. With the developed computational codes, we will perform benchmark and validation with two classes of materials, namely, MCl (M=Li, Na, K, Rb) and PbX (X=S, Se, Te). MCl compounds are chosen as a model system for validation due to their simple crystal structures, low concentrations of defects, and lack of electronic thermal transport, while PbX compounds are chosen because they are important thermoelectric materials [10]. In this project, we will perform first-principle density functional theory (DFT), Boltzmann transport equation (BTE) and classical molecular dynamics (MD) calculations to understand the effects of high-order PPIs on LTC. In the first part of this project, we will use CSLD to extract IFCs up to 4th-order for MCl (M=Li, Na, K, Rb), evaluate the phonon lifetime due to three- and four-phonon interactions and compute LTC using phonon BTE. We will further validate the BTE results with those obtained from MD-based Green-Kubo method [11] using the same set of IFCs. T he IFCs-based MD will be performed using our in-house lattice molecular dynamics (LMD) code. In the second part of this project, we will investigate both the phonon mode frequency shift and lifetime due to high-order PPIs in PbX (X=S, Se, Te) utilizing the renormalized IFCs extracted from CSLD, in which both temperature effect and lattice expansion will be considered. [1] F. J. DiSalvo, “Thermoelectric cooling and power generation”, Science 285, 703 (1999) [2] L. E. Bell, “Cooling, heating, generating power, and recovering waste heat with thermoelectric systems”, Science 321, 1457 (2008) [3] N. P. Padture, M. Gell and E. H. Jordan, “Thermal barrier coating for gas-turbine engine applications”, Science 296, 280 (2002) [4] http://miccom-center.org/ [5] A. J. H. Mcgaughey and M. Kaviany, “Phonon Transport in Molecular Dynamics Simulations: Formulation and Thermal Conductivity Prediction”, Adv. Heat Transfer, 39 (169-255) (2006) [6] Lucas Lindsay, “First Principles Peierls-Boltzmann Phonon Thermal Transport: A Topical Review”, Nanoscale and Microscale Thermophysical Engineering 20, 2 (2016) [7] F. Zhou, W. Nielson, Y. Xia, and V. Ozolins, “Lattice anharmonicity and thermal conductivity from compressive sensing of first-principles calculations”, Phys. Rev. Lett. 113, 185501 (2014) [8] T. Feng and X. Ruan, “Quantum mechanical prediction of four-phonon scattering rates and reduced thermal conductivity of solids”, Phy. Rev. B. 93, 045202 (2016) [9] O. Delaire, J. Ma, K. Marty, A. F. May, M. A. McGuire, M-H. Du, D. J. Singh, A. Podlesnyak, G. Ehlers, M. D. Lumsden, and B. C. Sales, “Giant anharmonic phonon scattering in PbTe”, Nat. Mater. 10, 614 (2011) [10] K. Biswas, J. He, I. D. Blum, C.-I Wu, T. P. Hogan, D. N. Seidman, V. P. Dravid, and M. G. Kanatzidis, “High-performance bulk thermoelectrics with all-scale hierarchical architectures”, Nature 489, 414 (2012) [11] M. S. Green, “Markoff random processes and the statistical mechanics of time‐dependent phenomena. II. Irreversible processes in fluids”, J. Chem. Phys. 22, 398 (1954); R. Kubo, “Statistical-mechanical theory of Irreversible processes. I. General theory and simple applications to magnetic and conduction problems”, J. Phys. Soc. Japan 12, 570 (1957) Project description: The calculations will involve the items below. (1) We will extract IFCs up to 4th-order for MCl (M=Li, Na, K, Rb) using forces from DFT (VASP) supercell (512 atoms) calculations. The efficient algorithm implemented within CSLD only requires about 100 supercell configurations with random atomic displacements for each compound due to high space group symmetry and the sparsity of IFCs space. (2) We will perform three- and four-phonon BTE calculation for MCl (M=Li, Na, K, Rb) and calculate lattice thermal conductivity from 100 to 800 K (every 100 K) using our in-house ShengBTE4th code. (3) We will perform classical lattice molecular dynamics simulations for MCl (M=Li, Na, K, Rb). For each compound and each temperature from 100 to 800 K (every 100 K), we will construct 512- and 1728-atom supercells, 10 different initial atomic configurations and simulate 1 ns length with time step of 1 fs using our in-house LMD code. (4) We will extract renormalized IFCs up to 4th-order for PbX (X=S, Se, Te) using forces from DFT supercell (128 atoms) calculations. For each compound, temperature-renormalized IFCs needs to extracted for each temperature (we choose 100, 300, 500 and 700 K) using temperature-dependent lattice parameters. (5) We will perform renormalized phonon, three- and four-phonon BTE calculations for PbX (X=S, Se, Te) and calculate lattice thermal conductivity from 100 to 800 K (every 100 K) using our in-house ShengBTE4th code. (6) We require additional core hours to perform code implementation and debug. The time estimates for the various parts above, based on benchmark results with VASP, CSLD, ShengBTE4th and LMD running on LCRC and NERSC, are listed below. (1) 4 compounds x 100 supercells x 192 core hours each = 76,800 (2) 4 compounds x 8 temperatures x 864 core hours each = 27,648 (3) 4 compounds x 8 temperatures x 2 supercells x 10 initial conditions x 120 core hours each = 76,800 (4) 3 compounds x 4 lattice parameters (temperatures) x 100 supercells x 384 core hours each = 460,800 (5) 3 compounds x 8 temperatures x 864 core hours each = 20,736 The total request is about 660,000 core-hours. Codes used and scaling efficiency 1. The DFT calculations will be performed using the plane wave code VASP, with GGA-PBEsol/PBE exchange correlation functional and projector augmented wave (PAW) treatment of core electrons. The VASP code is tested in Blues with a 350 electron system and 65%-80% scaling efficiency is obtained 64 to 128 cores compared to 16 cores. Given this performance, the VASP code has the efficiency to simulate large number configurations in reasonable amount of time. 2. Three- and four-phonon scattering rates and phonon BTE will be solved using an in-house code (ShengBTE4th) developed based on ShengBTE. Since four-phonon BTE consumes significantly larger amount of core hours than three-phonon BTE due to the dramatically increased scattering space satisfying energy and momentum conservation, our code distributes phonon mode scattering rates over various cores by taking advantage of OpenMPI. Based on our test on LCRC/NERSC, our code achieves about 75% scaling efficiency (288 cores on Blues and Edison compared to 16 cores on Blues and 24 cores on Edison). The interatomic force constants (IFCs), which are inputs for phonon BTE, will be extracted using an in-house implementation of CSLD, which is a serial code and essentially only takes minutes to complete a IFCs fitting procedure. 3. Classical molecular dynamics will be carried out with an in-house code called lattice molecular dynamics (LMD). This code, with OpenMP enabled, has been tested using a single node on LCRC/NERSC, achieving scaling efficiency of about 70% (16 cores on Blues and 24 cores on Edison compared to one cores). Dr. Yi Xia and Dr. Maria Chan will be responsible for carrying out the simulations. Industry partnership: Project URL: Requested allocation: 660000 Q1: 150000 Q2: 210000 Q3: 150000 Q4: 150000 Justification: Since most core hours will be used for supercell (more than 200 atoms) calculations performed using VASP in our project, we provide extra detailed scaling data and CPU performance analysis in addition to those listed above. VASP is tested on XSEDE (Extreme Science and Engineering Discovery Environment) HPC system (300 nodes, 8 cores per node) with number of electrons from ~1000 to ~6000 (~100 to ~600 atoms) using PBE exchange-correlation functional and kinetic cutoff of 350 eV. The scaling efficiency of 80% to150% is obtained for 128 to 1024 cores compared to 16 cores. Given this performance, the VASP has the reasonable efficiency to simulate large number of configurations in reasonable amount of time. Storage requirements: 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: reduceco2
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

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: Marton Voros Applicant's institution: ANL Applicant's division: MSD Project Name: reduceco2 Project title: Kinetics of CO2 reduction of clusters Associated funding: DOE BES AC0206CH11357 Other Systems: NERSC, 1.000.000 (project on nanoparticle solar cells) Science: In this project, we will investigate the kinetics of charge transfer for the electrochemical reduction of CO2 to CO on supported clusters. Efficiently and cheaply generating fuels using reducing CO2 to hydrocarbons is a prime target in the search for renewable energy materials and processes. A variety of catalysts have been discovered, and the catalytic properties have been elucidated using atomistic density functional theory techniques. The most common theory of the atomistic mechanism behind the first catalytic steps of reducing CO2 to CO is based on coupled electron and proton transfer on the surface of the catalyst yielding COOH. This scenario ignores the kinetics of electron transfer. Indeed, this theory is unable to explain recent experimental findings on transition metal clusters that showed that CO2 reduction is about 100 times more active than those reported on MoS2 nanoflakes (Science 353, 467 (2016)). Our primary goal in this project is to use our recently developed constrained density functional theory (CDFT) code (J. Chem. Theory Comput. 13, 2581 (2017)) to compute the electron transfer kinetics from transition metal clusters to CO2 and compare the performance of transition metal clusters to other known catalysts, such as surface of Cu or edges of MoS2 flakes. Finally, using our kinetic insights, we will rationalize recent experimental findings. We expect that the insights gained by computing the charge transfer kinetics, which are inaccessible in standard DFT calculations, will be imperative to design improved CO2 electrocatalysts. Project description: We will be using first principles methods based on density functional theory. In particular, for simulating the charge transfer from the transition metal clusters to CO2 we will be using the plane wave code Quantum Espresso (QE). QE can make use of efficient linear algebra (Lapack, BLAS, Scalapack, BLACS) and FFT libraries if they are available. QE was shown to efficiently scale to a few hundreds of processors in the case of non-hybrid functional calculations. Hybrid functional calculations can scale up to a few thousands of cores, especially because of recent methodological and algorithmic development (J. Chem. Theory Comput., 2012, 2242 (2016)). NERSC staff has recently restructured the algorithm behind hybrid functionals in Quantum-Espresso and has shown that this method is capable of making use of the new Cori KNL nodes due to its hierarchical, multi-level parallelization strategy that involves using several layers of MPI and OpenMP parallelizati on (e.g. http://www.nersc.gov/users/computational-systems/cori/application-porting-a…) We expect the same or similar benefits when using the KNL nodes of the new Bebop cluster for the hybrid functional calculations, however, we know from our experience that Quantum-Espresso also runs fine on the Blues cluster and we expect it can also nicely run on the broadwell nodes. Indeed, our initial tests on small systems during the early user access program showed good performance. Since our preliminary tests showed that hybrid functional calculations are necessary to get physically meaningful results, we will plan to exclusively use 100% of our allocation on hybrid functional calculations. Further, for the time being, we will neglect the effect of the support (in the experiments it is glassy carbon or reduced graphene oxide), although we will plan to estimate its importance using our recently developed computationally efficient technique that includes a model electrode through electrostatic interactions (Chem. Mater. 29, 1255 (2017)). To simulate charge transfer processes, we will use our own implementation of constrained DFT (CDFT) to localize charges on either the catalyst or CO2 and then to compute all the parameters (including electronic coupling, reorganization energy, driving force) entering semi-empirical charge transfer models, such as Marcus-theory. Our own implementation of CDFT is integrated into a private version of the most recent release of Quantum-Espresso and it inherits its performance, although typical CDFT calculations are about one order of magnitude more expensive since they require a double self-consistent cycle instead of the regular single self-consistent cycles. We will focus on five different catalysts: W4, W3MO, W2MO2, WMo3 and Mo4, since most of these are available to our experimental collaborators. Having found the ground state geometry (this will take a negligibly small amount of time), we will then simulate charge transfer from these clusters to CO2 in the gas phase. We will investigate the charge transfer kinetics by computing the electronic coupling as a function of distance and also the angle of CO2 since it is known that reduced CO2 (anion radical) traps the excess electron by bending. We estimate to use a coarse sampling of 8 angles and 8 distances for each of the systems. Altogether we plan to run 64 constrained DFT calculations for each system, which amounts to 320 calculations. Given that each CDFT calculation requires a "donor" and "acceptor" calculation, this means 640 double self-consistent hybrid functional calculations. Furthermore, to compute the reorganization energies and driving forces we will have to optimize the structure in the presence of the constraints which amounts to about 20 regular CDFT steps per cluster per site. Our preliminary estimate suggests that we can use about 128 cores (assuming KNL nodes) per calculation and each calculation would take about two hours. Finally, we will compare our results to other known catalysts, such as Cu clusters and MoS2 nanoflakes. We will take literature structures on Cu3, Cu4 (J. Am. Chem. Soc. 137, 8676 (2015)), which will amount to 2/5 of the time estimated for the calculations on the WMo clusters. Finally, we will use a recently published cluster model of MoS2 to simulate CO2 reduction on MoS2 nanoflakes (J. Am. Chem. Soc. 137, 6692 (2015)). Since this cluster is about twice as large and our calculations scale as N^4, where N is the characteristic system size, we estimate to spend almost as much time simulating this one cluster than for all the Cu and WMo clusters together. All in all, we request 440.000 core hours for the entire year evenly distributed. For the reasons discussed above, we believe that our hybrid functional calculations can really benefit from using the KNL nodes, however, we can definitely use the broadwell nodes efficiently and we had a successful experience in using Quantum-Espresso of Blues. Industry partnership: Project URL: Requested allocation: 440000 Q1: 110000 Q2: 110000 Q3: 110000 Q4: 110000 Justification: Storage requirements: 1 TB. We will need to, at least temporarily, save wave functions and charge densities to enable efficient restarts of QE calculations. Since these quantities are saved on grids and can be several tens of GBs in size, we estimate we will need about 1 TB of storage. 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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New LCRC report submitted for CrysGrowKMC
by support＠lcrc.anl.gov 07 Sep '17

07 Sep '17

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2017/?project=CrysGrowKMC

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[LCRC Accounts] Yearly Allocation Request for Anharmonic_systems
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Darya Aleinikava Project Name: Anharmonic_systems Division: CSE Project title: Analysis of dynamical complexities of highly anharmonic systems Associated funding: Other Systems: High-performance GPU cluster Golem Science: The goal of this project is to continue the study of the dynamical complexities of systems with arbitrary degree of anharmonicity. The first objective of this work is to calculate the exact density of states (DOS) of finite-size systems, such as atomic clusters, and to use it to analyze their properties as a function of composition and size. DOS is the central figure of statistical mechanics since it is the basis for computation of all the other statistical mechanical characteristics, and it also plays a major role in theories of chemical kinetics because it allows a direct evaluation of reaction rate constants. The non-trivial problem of finding DOS for arbitrarily anharmonic systems has been researched extensively over the last 60 years, but no exact solution that would be applicable in all cases was found. We developed the exact solution in the frameworks of both classical and quantum mechanics and implemented it in the form of efficient algorithms. The solution involves MD simulations and analysis of data generated dynamically. Specifically, will produce power spectra, which serve as an input into t he newly developed algorithms, yielding the exact anharmonic density of states thus eliminating the need to use various approximations. As the second aspect of the project we will address the problem of mixing in heterogeneous systems, where we plan to utilize such descriptors as mixing coefficient and dynamical degree of freedom, collected during MD simulation runs, to investigate the structural changes of different isomers during high-energy dynamics which is of particular importance in the study of multiple-steps melting transitions. Project description: We are planning to build on the results obtained from previous years, and continue to work on thermal behavior of homogeneous and heterogeneous clusters. We will mainly focus on new tools that could potentially be very effective in catching solid-like and liquid-like transitions in such clusters, and analyze the transitions as a function of cluster size and/or composition. The systems to be utilized for the analysis include bi-metallic Al/Ni clusters, and during MD runs we will be concentrating on such novelty tools as mixing coefficients and dynamical degrees of freedom, which will be accompanied by a more widely used set of descriptors as caloric curves, RMS bond length fluctuations, heat capacities, power spectra, and DOS. We will pay special attention to the phenomenon of apparent similarity of dynamical degrees of freedom of different clusters subsystems at usually low energies, i.e., the “chameleon effect,” see if this effect is exaggerated by the anharmonicity of the potential, and how it is affected by the size/composition of the cluster (we will analyze the clusters of sizes ~10^2 atoms and up.) For the completion of the work outlined above and the collection of all the necessary descriptors, the average MD run for a single cluster of a specific composition will require, on average, 16 cores/node * 5 nodes * 110 hours of run time = 8,800 core-hours. We estimate that we will study 50 different clusters of various sizes and compositions. Therefore we project that the total computational time will be 8,800 core-hours*50 structures+2000 hours development = 442,000 core-hours. Out of requested 442,000 core-hours, 2% of the time will be allocated for single-core jobs. The number of people to run these simulations is 2. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 442000 Q1: 110500 Q2: 110500 Q3: 110500 Q4: 110500 Justification: Storage requirements: Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for Meso_Nuclear
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Linyun Liang Project Name: Meso_Nuclear Division: MCS Project title: Gas bubble kinetics in an irradiated U-Mo using a mesoscale simulation approach Associated funding: Nuclear energy system Other Systems: Science: High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. Uranium-molybdenum (U-Mo) alloy fuel dispersed in an aluminum matrix was identified as a potential fuel type. However, irradiation tests have shown that fuel operating at higher temperatures and powers cause the U-Mo fuel powder in the meat to react with and almost completely deplete the aluminum in the matrix. It is anticipated that replacing dispersion fuel with a monolithic fuel type can solve both the U-Al interaction and fuel density loading problems. In monolithic fuel the entirety of the fuel meat is comprised of a single foil of the fuel alloy. This fuel type represents the optimum in fuel meat density. The greatly reduced fuel surface area per unit mass and the fact that fuel-aluminum interfaces are in the cooler region of the plates should minimize the fuel-aluminum reaction. We will study the effect of U235 uniformity in U-Mo fuel on the fuel swelling behaviors. The simulations will be performed using MOOSE software developed by Idaho National Laboratory. Project description: We will develop a new phase-field model to incorporate the effect of U235 uniformity in the nucleation and formation of gas bubbles, as well as the coupling with the recrystallization. We will use our developed model to study the effect of U235 distribution on the fission rate. The events employed in the simulation are the absorption and emission of a vacancy, a SIA, and an interstitial U by a single Xe bubble, while an event associated with SIA loops or substitutional U is neglected here for simplicity. We will systematically investigate the effect of Xe, vacancy, and SIA concentration, fission defect generation and their recombination, sink strength, grain boundaries, and elastic interaction on the growth kinetics of gas bubble with the uniformity of U235. The swelling of U-Mo due to fission gas bubble will be simulated and compared to experimental observations. Our study aims to provide insight into understanding of the effect of fabrication condition on gas swelling in irradiated U-Mo materials. In our phase field model, we have four highly non-linear, coupled partial differential equations for phase-field parameter, vacancy composition, SIA composition, and gas atom composition, which must be solved numerically. In the meaning time, the elastic equilibrium equation is also included in each time step, which requires to obtain the elastic solution at the equilibrium state for each time step and can significantly increase the cost of the simulation time. And also in order to avoid the partial loss of interfacial energy, we will extend our model to three dimensional system. Therefore, to effectively solve this problem, we will need about 100,000 core hours including the 4,000 core-hour to debug and test the algorithm and code and 96,000 core-hours (4 cores * 16 nodes * 10 hours of run time * 150 different runs) for the nucleation and growth of gas bubbles calculations. In conclusion, the total core-hours requested for this project throughout the FY2018 will be 100,000 core-hours. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 100000 Q1: 25000 Q2: 25000 Q3: 25000 Q4: 25000 Justification: Storage requirements: 1TB Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for Bio_catalysis
by accounts＠lcrc.anl.gov 07 Sep '17

07 Sep '17

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Cong Liu Project Name: Bio_catalysis Division: MSD Project title: Single-site Catalysis Associated funding: Director's Fellowship at Argonne Other Systems: Science: The central theme of the Catalysis Science Program is to develop well-defined, single-site, supported catalysts for kinetically limited transformations (e.g., alkane C–H activation and functionalization) and the mechanisms by which these occur. In particular, the principal goal in the current proposal involves optimum control of catalyst efficiency and selectivity for alkane C-H/C-C transformation reactions, including alkane dehydrogenation and non-oxidative methane coupling, respectively. The energy input required to drive such reactions could compromise the stability and selectivity of traditional heterogeneous catalysts, resulting in a distribution of reaction products, or compromise the stability of homogeneous active sites, leading to catalyst deactivation. During the previous performance period, we demonstrated that our catalysts are very stable and provide a well-defined system with which to understand how rationally tuning the electronic properties of single-atom catalysts can lead to higher performance. Using these catalysts, along with our knowledge of single-site catalysis, we plan to elucidate the relationship between their structures and the mechanisms of alkane C–H bond activation. This is expected to provide fundamental information pertinent to the rational design of functional alkane upgrading catalysts. This goal warrants the merging of ideas and approaches from bridging heterogeneous and homogeneous catalysis, kinetics, and reaction engineering. The fundamental understanding and catalysis of these reactions are critical to energy conversion applications such as biomass conversion. This research is directly related to the BES and office of science mission and under their support. Project description: In the proposed research, we will focus on understanding how tuning the electronic properties of single ions can accelerate the rate-determining step of catalytic alkane activation for the dehydrogenation of light alkanes and non-oxidative methane coupling, of interest to DOE and very important reactions in the energy sector. In particular, we will focus on how the metal support (ligand) bonds alter catalytic activity and selectivity for the C-H activation versus C-C bond formation. Using the modern tools of synthesis, structure determination, and theory available for well-defined catalytic systems, we will investigate reaction mechanisms, develop structure-activity relationships, and use these relationships to design new catalysts with superior activity, stability, and selectivity for activation of C-H bonds versus C-C bond formation. The following calculations will be carried out: 1. Development of computational activity descriptors for catalytic hydrogenation and dehydrogenation. Our previous studies have found that reaction energetics of critical elementary step can be strongly correlated with the activity of the single-site catalyst. We will, in the following year, carry out extensive DFT and microkinetic modeling to investigate the rationale of the correlations between the reaction energetics and the activity and develop a more rigorous relationship. 2. Support and promoter effects will be investigated for single-site catalysts. SiO2, Al2O3, ZrO2, and sulfated surfaces will be taken into account for the support effect. The electronic and structural effects will both be investigated. The functions and sulfate groups on the supported will be studies explicitly. On the other hand, metal oxide promoters through atomic layer deposition (ALD) technique have been found experimentally effective for promoting the catalytic activity of single-site catalysts. Our studies on promoter effects will be focused on two aspects: the electronic effect that affecting the catalytic activity, and stabilization effect of the promoter oxide which react with the single-atom catalyst site more effectively during the grafting reaction of the single atom ion. The calculations of this project will include both molecular (Gaussian) and periodic calculations (VASP). For Gaussian calculations, each calculation will take 1 processor for approximately 20-40 hours. For VASP calculations, each calculation will take 64 processors for about 20 hours. Approximately 800 gaussian calculations and 300 VASP calculations are required. Thus totally about 420000 cpu hours are necessary. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 420000 Q1: 105000 Q2: 105000 Q3: 105000 Q4: 105000 Justification: Storage requirements: Thank You, The LCRC Accounts System

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