Global Arrays
Encyclopedia
Global Arrays, or GA, is the library developed by scientists at Pacific Northwest National Laboratory
for parallel computing. GA provides a friendly API for shared-memory programming on distributed-memory computers for multidimensional arrays. The GA library is a predecessor to the GAS (global address space) languages currently being developed for high-performance computing.
The GA toolkit has additional libraries including a memory allocator, ARMCI, and functionality for out-of-core storage of arrays (ChemIO). Although GA was initially developed to run with TCGMSG, a message communicator that came before the MPI standard (Message Passing Interface
), it is now fully compatible with MPI. GA includes simple matrix computations (matrix-matrix multiplication, LU solve) and works with ScaLAPACK
. Sparse matrices are available but the implementation is not optimal yet.
GA was developed by Jarek Nieplocha, Robert Harrison and R. J. Littlefield. The ChemIO library for out-of-core storage was developed by Jarek Nieplocha, Robert Harrison and Ian Foster
.
The GA library is incorporated into many quantum chemistry packages, including NWChem
, MOLPRO
, UTChem, MOLCAS
, and TURBOMOLE
.
The GA toolkit is free software
, licensed under a self-made license.
Pacific Northwest National Laboratory
Pacific Northwest National Laboratory is one of the United States Department of Energy National Laboratories, managed by the Department of Energy's Office of Science. The main campus of the laboratory is in Richland, Washington....
for parallel computing. GA provides a friendly API for shared-memory programming on distributed-memory computers for multidimensional arrays. The GA library is a predecessor to the GAS (global address space) languages currently being developed for high-performance computing.
The GA toolkit has additional libraries including a memory allocator, ARMCI, and functionality for out-of-core storage of arrays (ChemIO). Although GA was initially developed to run with TCGMSG, a message communicator that came before the MPI standard (Message Passing Interface
Message Passing Interface
Message Passing Interface is a standardized and portable message-passing system designed by a group of researchers from academia and industry to function on a wide variety of parallel computers...
), it is now fully compatible with MPI. GA includes simple matrix computations (matrix-matrix multiplication, LU solve) and works with ScaLAPACK
ScaLAPACK
The ScaLAPACK library includes a subset of LAPACK routines redesigned for distributed memory MIMD parallel computers. It is currently written in a Single-Program-Multiple-Data style using explicit message passing for interprocessor communication...
. Sparse matrices are available but the implementation is not optimal yet.
GA was developed by Jarek Nieplocha, Robert Harrison and R. J. Littlefield. The ChemIO library for out-of-core storage was developed by Jarek Nieplocha, Robert Harrison and Ian Foster
Ian Foster
Ian Foster is a Distinguished Fellow and the Associate Division Director in the Mathematics and Computer Science Division at Argonne National Laboratory, where he leads the Distributed Systems Laboratory, and he is a Professor in the Department of Computer Science at the University of Chicago...
.
The GA library is incorporated into many quantum chemistry packages, including NWChem
NWChem
NWChem is an ab initio computational chemistry software package which also includes quantum chemical and molecular dynamics functionality.It was designed to run on high-performance parallel supercomputers as well as conventional workstation clusters. It aims to be scalable both in its ability to...
, MOLPRO
MOLPRO
MOLPRO is a software package used for accurate ab initio quantum chemistry calculations. It is developed by Peter Knowles at Cardiff University and Hans-Joachim Werner at Universität Stuttgart in collaboration with other authors....
, UTChem, MOLCAS
MOLCAS
MOLCAS is an ab initio computational chemistry program, developed at Lund University in collaboration with others. Focus in the program is placed on methods for calculating general electronic structures in molecular systems in both ground and excited states. MOLCAS is, in particular, designed to...
, and TURBOMOLE
TURBOMOLE
TURBOMOLE is an ab initio computational chemistry program that implements various quantum chemistry algorithms. It is developed at the group of Prof. Reinhart Ahlrichs at the University of Karlsruhe....
.
The GA toolkit is free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
, licensed under a self-made license.