BES Requirements Worksheet

1.1. Project Information - Computational Studies in Molecular Geochemistry

2. Project Summary & Scientific Objectives for the Next 5 Years

Please give a brief description of your project - highlighting its computational aspect - and outline its scientific objectives for the next 3-5 years. Please list one or two specific goals you hope to reach in 5 years.

Our effort consists of molecular level simulations in key areas of geochemistry. geochemical areas include: 
 
Interactions between Fe(III) reducing bacteria and iron-oxides - We are using ab initio molecular modeling calculations of structures of anthraquinone reductant species and Fe(III)-oxide surfaces to produce a kinetic model of heterogeneous electron transfer reactions with implications for biogeochemical activity in subsurface environments.  
 
Mineral surface interactions - This project is directed at providing a molecular scale understanding of surface complexation reactions at oxide, oxyhydroxide, and silicate minerals through the use of molecular modeling calculations.  
 
Supercritical behavior of Ore Forming Fluids- This project is using first principles molecular dynamic simulations to improve our understanding of natural processes that lead to the concentration of metal species in natural waters and deposition of ore rich formations.  
 
The Reaction Specificity of Nanoparticles in Solution - Application to the Reaction of Nanoparticulate Iron and Iron Compounds with Chlorinated Hydrocarbons This project is using first principles simulations to model and characterize the mechanism the dissociative reduction of halogenated hydrocarbons by iron-oxide and nanoparticulate iron systems. 

3. Current HPC Usage and Methods

3a. Please list your current primary codes and their main mathematical methods and/or algorithms. Include quantities that characterize the size or scale of your simulations or numerical experiments; e.g., size of grid, number of particles, basis sets, etc. Also indicate how parallelism is expressed (e.g., MPI, OpenMP, MPI/OpenMP hybrid)

Classical molecular dynamics, ab initio molecular dynamics, electronic structure theory (e.g. MP2, CCSD(T), DFT) 
 
These calculations are performed using NWChem, Molpro, and various research codes.  
 
The parallelism in these programs are expessed using GA tools, MPI, hybrid MPI/OpenMP 

3b. Please list known limitations, obstacles, and/or bottlenecks that currently limit your ability to perform simulations you would like to run. Is there anything specific to NERSC?

Memory Speed,interconnect_speed,Algorithm Scaling,Point-to-point latency,Point-to-point bandwidth,Broadcast performance,all-reduce performance 

3c. Please fill out the following table to the best of your ability. This table provides baseline data to help extrapolate to requirements for future years. If you are uncertain about any item, please use your best estimate to use as a starting point for discussions.

Please list any required or important software, services, or infrastructure (beyond supercomputing and standard storage infrastructure) provided by HPC centers or system vendors.

Global Arrays  

4. HPC Requirements in 5 Years

4a. We are formulating the requirements for NERSC that will enable you to meet the goals you outlined in Section 2 above. Please fill out the following table to the best of your ability. If you are uncertain about any item, please use your best estimate to use as a starting point for discussions at the workshop.

4b. What changes to codes, mathematical methods and/or algorithms do you anticipate will be needed to achieve this project's scientific objectives over the next 5 years.

Highly scalable implementations for AIMD w/ hybrid DFT and MP2 are being developed. 
 
Highly scalable implementations of high level ab initio methods are being developed 
 
Current implementations readily scale to at least 30,000 cpus 
 
Hybrid MPI/openMP, GA/openMP MPI/CUDA, GA/CUDA algorithms are being developed to improve FLOP rates 
 
An DOE ASCR research project “Automatic transformation of MPI programs” is being pursued with S.Baden (UCSD) and D. Quinlan (LLNL) to improve the overlap of computation and communication in NWChem. 

4c. Please list any known or anticipated architectural requirements (e.g., 2 GB memory/core, interconnect latency < 3 #s).

4d. Please list any new software, services, or infrastructure support you will need over the next 5 years.

Tools for Hybrid programing OpenCL, HPPM?? 

4e. It is believed that the dominant HPC architecture in the next 3-5 years will incorporate processing elements composed of 10s-1,000s of individual cores, perhaps GPUs or other accelerators. It is unlikely that a programming model based solely on MPI will be effective, or even supported, on these machines. Do you have a strategy for computing in such an environment? If so, please briefly describe it.

Yes, see 4b 

New Science With New Resources

To help us get a better understanding of the quantitative requirements we've asked for above, please tell us: What significant scientific progress could you achieve over the next 5 years with access to 50X the HPC resources you currently have access to at NERSC? What would be the benefits to your research field if you were given access to these kinds of resources?

Please explain what aspects of "expanded HPC resources" are important for your project (e.g., more CPU hours, more memory, more storage, more throughput for small jobs, ability to handle very large jobs).

Predictive models could be developed for mineral-water interfaces and the nanoparticle-water interfaces. 
 
Access to large numbers of cpus (>10,000) for extended periods of time.