Curriculum Vitae


Doctor of Philosophy, Physics, Wake Forest University, Winston Salem, NC. (2013)
Related Course Work
Quantum Mechanics, Continuum Mechanics, Solid State Physics, Electromagnetism,
Statistical Mechanics, Group Theory
Master of Science, Computer Science, Wake Forest University, Winston Salem, NC. (2008)
Related Course Work
Numerical Nonlinear Optimization, Parallel Algorithms, Bioinformatics, Database
Bachelor of Science, Computer Science, University of Tennessee, Knoxville, TN. (2006)
Related Course Work
Mathematical Modeling, Systems Programming, Graphics Programming, Software
Ph.D. Research
Calculating Magnetic Properties in Condensed Matter Systems

This work expanded and utilized ab initio computational techniques for calculating magnetic properties such as the orbital magnetization and nuclear magnetic resonance chemical shielding of infinitely periodic systems. It included development of the necessary extensions to the current theoretical methods, the code that implements these methods, and calculations on materials of interest using the techniques.

M.S. Research
A Computational Method to Explore the Time Evolution of Protein Cavities

This thesis presented a tool for analyzing molecular dynamics simulations by tracking and visualizing protein cavity evolution through time. This was done in order to examine the impact of negative space on protein allostery.


2020–present Product Manager, HPC SDK and HPC Compilers at NVIDIA - Knoxville, TN
HPC compiler and developer productivity
  • Set roadmaps for HPC compiler and developer kit products
  • Increase scientific productivity by developing programming model strategies with implementers and customers
2018–2020 HPC Systems Engineer at Oak Ridge National Laboratory - Oak Ridge, TN
Leadership system support and C++ application development
  • Provide system support for Summit supercomputer and all other HPC resources at the Oak Ridge Leadership Computing Facility
  • Focused software engineering for two HPC applications in ab-initio materials and fusion energy domains
2016–2018 Computer Scientist at Oak Ridge National Laboratory - Oak Ridge, TN
Application readiness and programming model co-design for upcoming high-performance computing architectures
  • Implemented new algorithms for petascale quantum materials application
  • Built static-anlaysis tool for applications to inform programming model design
2014–2016 Postdoctoral Researcher at Oak Ridge National Laboratory - Oak Ridge, TN
Researching programming models and preparing facility programming environments for the CORAL architecture
  • Studied performance portability of upcoming programming models for heterogeneous architectures
  • Organized multiple workshops resulting in published research proceedings
  • Managed community activity and development of the OpenSHMEM specification
  • Developed HPC strategy for quantum computing simulator
2012–2014 Research Scientist at Georgia Institute of Technology / ORNL - Oak Ridge, TN
Advanced user and applications support for the Keeneland project
  • Optimized numerical algorithms for GPU-specific science applications
  • Implemented accelerator kernels for the SHOC HPC benchmark suite
  • Addressed user issues with installed applications on Keeneland coming from multiple scientific domains
2012 Intern at National Institute of Computational Sciences (NICS) - Oak Ridge, TN
GPU-specific benchmarking and developer documentation for the Keeneland System
  • Developed example GPU code for SGEMM kernel using Cuda, OpenCL, Cublas, Magma, MPI
  • Demonstrated simple performance analyses to be considered when using GPU-acceleration
  • Produced documentation resources for using and scaling scientific codes on a GPU compute cluster

2008–2012 Research Assistant at Wake Forest University - Winston Salem, NC

  • Implemented and applied new methods for calculating materials properties in quantum mechanics code
  • Created molecular dynamics simulation analysis and visualization tool

2006–2008 Teaching Assistant at Wake Forest University - Winston Salem, NC

  • Evaluated student progress and delivered final grades for weekly homework and lab assignments
  • Prepared, tested, and presented lectures for weekly programming labs
  • Conducted tutorial sessions for large groups and class sections

2003–2006 Unix Systems Administrator at Dept. of Computer Science, University of Tennessee - Knoxville, TN

  • Responsible for maintaining high availability (HA) of disk and authentication LDAP services with load balancing and automatic failover
  • Deployed and maintained network and compute infrastructure using technologies like LDAP, CfEngine, Postfix, Nagios, SSL, Apache, MySQL, Courier IMAP
  • Installed and maintained hardware for department servers, labs, and clusters; provided primary support for faculty and researchers; wrote internal and external system documentation

Publications and Presentations

Enabling ISO Standard Languages for Complex HPC Workflows
M. Graham Lopez, Jeff R. Hammond, Jack C. Wells, Tom Gibbs, and Timothy B. Costa
2022 Proceedings of the 2021 Smoky Mountains Workshop (Springer CCIS, volume 1512, pages 301-309)
Accelerating Standard C++ with GPUs Using stdpar
David Olsen, M. Graham Lopez, and Bryce Adelstein Lelbach
Accelerating Fortran DO CONCURRENT with GPUs and the NVIDIA HPC SDK
Guray Ozen and M. Graham Lopez
MemBrain: Automated Application Guidance for Hybrid Memory Systems
M. B. Olson, T. Zhou, M. R. Jantz, K. A. Doshi, M. G. Lopez, and O. Hernandez
2018 IEEE International Conference on Networking, Architecture and Storage (NAS)
Compile-Time Library Call Detection Using CAASCADE and XALT
Jisheng Zhao, Oscar Hernandez, Reuben Budiardja M. Graham Lopez, Vivek Sarkar and Jack C. Wells
2018 International Workshop on OpenPOWER for HPC (IWOPH 2018)
QMCPACK: An open source ab initio Quantum Monte Carlo package for the electronic structure of atoms, molecules, and solids
J. K A Baczewski, et al.
2018 Journal of Physics: Condensed Matter
Using CAASCADE and CrayPAT for analysis of HPC applications
Reuben D. Budiardja, M. Graham Lopez, Jisheng Zhao, Oscar Hernandez, Vivek Sarkar, and Jack C. Wells
2018 Proceedings of Cray User Group
Sparse Grid Methods for Solving Vlasov-Poisson and Vlasov-Maxwell Systems
L. Mu, D. Green, E. D’Azevedo, T. Wang, W. Elwasif, T. McDaniel, and M. G. Lopez
2018 APS Meeting Abstracts
CAASCADE: A system for static analysis of HPC software application portfolios
M. Graham Lopez, Oscar Hernandez, Reuben D. Budiardja, and Jack C. Wells
2017 Workshop on Extreme-Scale Programming Tools
Evaluation of Directive-based Performance Portable Programming Models
M. Graham Lopez, Wayne Joubert, Ver'onica Vergara Larrea, et al.
2017 International Journal of High Performance Computing and Networks
Enabling One-Sided Communication Semantics on ARM
Pavel Shamis, M. Graham Lopez, Gilad Shainer
2017 Parallel and Distributed Processing ymposium Workshops}
Challenges of OpenACC Performance Portability
M. Graham Lopez and Oscar Hernandez
2017 OpenACC for Programmers - Concepts and Strategies (book chapter)
OpenACC 2.5 Validation Testsuite Targeting Multiple Architectures
Kyle Friedline, Sunita Chandrasekaran, M. Graham Lopez, Oscar Hernandz
2017 Second Workshop on Performance Portable Programming Models for Accelerators
Supporting Distributed and Heterogeneous Programming Models in ISO C++
M. Graham Lopez, Michael Wong, Gordon Brown
2017 Distributed and Heterogeneous Programming in C and C++ (abstract/presentation)
Effective Vectorization with OpenMP 4.5
Joseph N. Huber, Oscar Hernandez, and M. Graham Lopez
2017 Oak Ridge National Laboratory (technical report)
Towards Achieving Performance Portability Using Directives for Accelerators
M. Graham Lopez, Ver'onica Vergara Larrea, Wayne Joubert, et al.
2016 Third Workshop on Accelerator Programming Using Directives
Using C++ AMP to Accelerate HPC Applications on Multiple Platforms
M. Graham Lopez, Christopher Bergstrom, Ying Wai Li, Wael Elwasif, and Oscar Hernandez
2016 First Workshop on Performance Portable Programming Models for Accelerators
Early Experiences Writing Performance Portable OpenMP 4 Codes
Veronica Vergara Larrea, Wayne Joubert, M. Graham Lopez, and Oscar Hernandez
2016 Proc. Cray User Group
Compiler-based software analysis toolkit for climate model development
Dali Wang, Oscar Hernandez, M. Graham Lopez, Frank Winkler, and Michael Wolfe
2016 Advanced X-cutting Ideas for Computational Climate Science
OpenSHMEM and Related Technologies. Experiences, Implementations, and Technologies
Manjunath Gorentla Venkata, Pavel Shamis, Neena Imam, and M. Graham Lopez
2015 Springer Verlag (proceedings)
Examining recent many-core architectures and programming models using SHOC
M. Graham Lopez, Jeffrey Young, Jeremy S. Meredith, et al.
2015 Proceedings of the 6th International Workshop on Performance Modeling, Benchmarking, and Simulation of High Performance Computing Systems (PMBS’15)
UCX: An Open Source Framework for HPC Network APIs and Beyond
Pavel Shamis, M. Graham Lopez, Matthew B. Baker, et al.
2015 High-Performance Interconnects (HOTI’15)
An Evaluation of OpenSHMEM Interfaces for the Variable-Length AlltoallV() Collective Operation
M. Graham Lopez, Pavel Shamis, and Manjunath Gorentla Venkata
2015 2nd Workshop on OpenSHMEM and Related Technologies
Exploring OpenSHMEM Model to Program GPU-based Extreme-Scale Systems
Sreeram Potluri, Davide Rossetti, Donald Becker, et al.
2015 2nd Workshop on OpenSHMEM and Related Technologies
Large-scale Hydrodynamic Brownian Simulations on Multicore and GPU Architectures
M. Graham Lopez, Mitchel Horton, and Edmond Chow
2014 Proceedings of the 2014 Annual Conference on Extreme Science and Engineering Discovery Environment
Advanced Application Support for Improved GPU Utilization on Keeneland
Jeffrey Young, M. Graham Lopez, Mitchel Horton, Richard Glassbrook, and Jeffrey S. Vetter
2014 The 3rd Conference of the Extreme Science and Engineering Discovery Environment (XSEDE ‘14)
Batch Matrix Exponentiation
M. Graham Lopez and Mitchel D. Horton
2014 Numerical Computations with GPUs, Springer, New York (book chapter)
Using NMR to study small molecule adsorption in metal organic frameworks
M. G. Lopez, Pieremanuele Canepa, and T. Thonhauser
2013 American Physical Society Annual March Meeting (presentation)
NMR Study of Small Molecule Adsorption in MOF-74-Mg
M. G. Lopez, Pieremanuele Canepa, and T. Thonhauser
2013 J. Chem. Phys. 138, 154704
A Quickstart Guide to Keeneland: Considerations for Effectively Incorporating GPUs
M. G. Lopez and Bruce Loftis
2012 The 1st Conference of the Extreme Science and Engineering Discovery Environment (XSEDE ‘12 - poster)
Wannier-based calculation of the orbital magnetization in ferromagnets
M. G. Lopez, David Vanderbilt, T. Thonhauser, and Ivo Souza
2012 Phys. Rev. B 85, 014435
Ab initio calculation of indirect spin-spin coupling constants
M. G. Lopez and T. Thonhauser
2012 Electronic Structure Workshop (poster)
Ab initio calculation of the orbital magnetization by Wannier interpolation
M. G. Lopez and T. Thonhauser
2011 American Physical Society Annual March Meeting (presentation)
Ab initio converse NMR approach for pseudopotentials
D. Ceresoli, N. Marzari, M. G. Lopez, and T. Thonhauser
2010 Phys. Rev. B 81, 184424
Converse NMR with pseudopotentials
M. G. Lopez, D. Ceresoli, and T. Thonhauser
2010 American Physical Society Annual March Meeting (presentation)
Converse NMR with pseudopotentials
M. G. Lopez and T. Thonhauser
2010 Wake Forest University Graduate Research Symposium (poster)
Procavo: a method for visualization of time dependence in protein cavities
M. G. Lopez and J. Fetrow
2008 Wake Forest University Graduate Research Symposium (poster)

Service and Committees

2017-2021: ISO C++ Standards Committee - Voting Representative
2016-2018: International Workshop on Performance Portable Programming Models for Accelerators (P3MA, co-located with ISC) - Co-Organizer/Program Co-Chair
2016-2018: International Workshop on OpenPOWER for HPC (IWOPH, co-located with ISC) - Program Committee Co-Chair
2017-2018: Distributed and Heterogeneous Programming in C and C++ (DHPCC++, co-located with IWOCL - Committee Member
2018: Supercomputing (SC) Panels Committee - Committee Member
2018: 23rd International Workshop on High-Level Parallel Programming Models and Supportive Environments - Committee Member
2017: IEEE International Parallel and Distributed Processing - Committee Member
2017: International Journal of Computer Science and Engineering - Guest Editor
2016-2017: Supercomputing (SC) Tutorials Committee - Committee Member
2016: 22nd International European Conference on Parallel and Distributed Computing (Euro-Par 2016) - Program Committee Member
2015: OpenSHMEM and Related Technologies Workshop (OpenSHMEM 2015) - Technical Program Chair

Honors and Awards

2016: Oak Ridge National Laboratory Significant Achievement Award
2012: XSEDE Student Engagement Program Award
2010-2011: Graduate Alumni Travel Award
2010: Sigma Pi Sigma Physics Honor Society
2009: Upsilon Pi Epsilon Computer Science Honor Society
2008: Runner-up Best Poster Mathematical Sciences Category Graduate Research Day, WFU
2006: Outstanding CS Graduate Award College of Arts and Sciences, UTK
2006: Phi Beta Kappa Honor Society