Global Arrays, or GA, is the library developed by scientists at Pacific Northwest National Laboratory for parallel computing. GA provides a friendly

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

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 (MA), Aggregate Remote Memory Copy Interface (ARMCI), and functionality for out-of-core storage of arrays (ChemIO). Although GA was initially developed to run with TCGMSG, a message passing library 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 The ScaLAPACK (or Scalable LAPACK) 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 interproc ...

. Sparse matrices are available but the implementation is not optimal yet. GA was developed by Jarek Nieplocha, Robert Harrison, R. J. Littlefield, Manoj Krishnan, and Vinod Tipparaju. 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 NWChem is an ab initio computational chemistry software package which includes quantum chemical and molecular dynamics functionality. It was designed to run on high-performance parallel supercomputers as well as conventional workstation clusters. ...

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. The emphas ...

, UTChem,

MOLCAS MOLCAS is an ab initio computational chemistry program, developed as a joint project by a number of international institutes. MOLCAS is developed by scientists to be used by scientists. It is not primarily a commercial product and it is not sol ...

, and

TURBOMOLE TURBOMOLE is an ab initio computational chemistry program that implements various quantum chemistry methods. It was initially developed by the group of Prof. Reinhart Ahlrichs at the University of Karlsruhe. In 2007, TURBOMOLE GmbH, founded by ...

. The GA library is also incorporated into sub-surface cod
STOMP
ref> The GA toolkit is

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

, licensed under
self-made license

References

See also