User Services Group Staff

After working as a NERSC consultant, Jonathan became Group Leader of USG at the end of 2005. Jonathan still maintains an active interest in algorithms and techniques used by the chemistry and biology community at NERSC, and collaborates with a number of research groups nationwide. The past few years, he has also has particpated in benchmarking and procuring of new architectures for NERSC. As part of collaborations with the Future Technologies Group in CRD, and the NERSC Science Driven System Architecture Team, he has published several architecture evaluation studies, and looked at what it takes to move common simulation algorithms to exotic architectures.. Before coming to NERSC, he worked at the IBM Almaden Research Center, developing computational chemistry methods and software, applying it to technological problems. Jonathan holds a Ph.D. in theoretical chemistry from the University of Sheffield, UK, and has done postdoctoral work at the University of British Columbia, Canada.

Katie Antypas has experience with parallel code optimization, parallel algorithms, code porting and debugging, parallel I/O libraries, and user training. Before coming to NERSC, Katie worked at the ASC Flash Center at the University of Chicago supporting the FLASH code, a parallel adaptive mesh refinement astrophysics application. She has an M.S. in Computer Science from the University of Chicago and a B.A. in Physics from Wellesley College.

Richard Gerber is a consultant in NERSC's User Services Group, helping users run, debug, and optimize their codes. He is responsible for the design and technical content of NERSC's Web site. He also develops and implements Web technologies such as real-time displays of the status of NERSC machines and batch queues, and the NERSC Web-based accounting system. He implemented and maintains the Online Help Desk and NERSC CVS servers. Richard is the overall USG lead for NERSC SciDAC support, and works with the accelerator and astrophysics SciDAC projects.

Richard has a Ph.D. in physics (computational astrophysics) from the University of Illinois at Urbana-Champaign and completed a postdoctoral fellowship at NASA Ames Research Center. His home page is http://www.nersc.gov/~ragerber/.

Frank Hale, who got his first job as a computing consultant in 1975, has returned to his roots as a member of NERSC's User Services Group. In addition to regular stints as a consultant for NERSC users, Frank is also responsible for much of the third party software supporting NERSC's user community. Frank was the first person hired in the User Services Group when NERSC moved to Berkeley in 1996, but he took a year-and-a-half hiatus from User Services to be Computing Sciences' liaison to DOE. Before joining NERSC, Frank spent eleven years with Berkeley Lab's Earth Sciences Division. Frank has a B.S. in information and computer science from UC Irvine in 1981.

Eric Hjort is the PDSF Consultant. Previously Eric worked in the Relativisitic Nuclear Collisions Group in the Nuclear Science Division at Berkeley Lab.

Mike Stewart specializes in compiler and library issues. He was previously the Cray applications analyst for NERSC from 1992 to 2001. Mike has completed an A.B. in linguistics, an M.S. in applied mathematics, and graduate work in statistics.

Helen has worked on investigating how large scale scientific applications can be run effectively and efficiently on massively parallel supercomputers: design parallel algorithms, develop and implement computing technologies for science applications. Some of her experiences include climate models, distributed components coupling libraries, parallel programming paradigms, scientific applications porting and benchmarking. Helen has been a staff member at Scientific Computing Group of Computational Research Division at LBNL before she joins USG. Helen has a Ph.D. in Marine Studies and an M.S in Computer Information Science, both from the University of Delaware.

David Turner has experience in the design, implementation, debugging, and optimization of mathematical algorithms on a wide range of scalar, vector, and parallel computing architectures. He also has experience in porting, debugging, and optimizing clients' scientific applications. David implemented a distributed-memory parallel version of the popular commercial quantum chemistry code Gaussian. He earned a B.S. in Mathematics/Computer Science at Western Washington University.

Zhengji Zhao joined the NERSC Division after working for three years as a postdoc in the Computational Research Division's Scientific Computing Group. In SCG she developed two new methods for computational nanoscience: the linear scaling 3D fragment (LS3DF) method for large-scale electronic structure calculations, and a new motif-based Hessian matrix method to estimate a preconditioner for nanostructures, which speeds up the convergence of atomic relaxation by at least a factor of four. Zhengji received her Ph.D. in computational physics from New York University for developing the reduced density matrix (RDM) method for electronic structure calculations, a highly accurate alternative to wavefunction-based computational chemistry methods. She received an M.S. in computer science from the Courant Institute of Mathematical Sciences, New York University; an M.S. in theoretical physics from Peking University, Beijing, China; and a B.S. in theoretical physics from Jilin University, Changchun, China.