ACES (computational chemistry)
Encyclopedia
Aces II is an ab initio
computational chemistry
package for performing high-level quantum chemical ab initio calculations. Its major strength is the accurate calculation of atomic and molecular energies as well as properties using many-body techniques such as many-body perturbation theory (MBPT) and, in particular coupled cluster techniques to treat electron correlation. The development of ACES II began in early 1990 in the group of Professor Rodney J. Bartlett
at the Quantum Theory Project (QTP) of the University of Florida
in Gainesville. There, the need for more efficient codes had been realized and the idea of writing an entirely new program package emerged. During 1990 and 1991 John F. Stanton, Jürgen Gauss, and John D. Watts, all of them at that time postdoctoral researchers in the Bartlett group, supported by a few students, wrote the backbone of what is now known as the ACES II program package. The only parts which were not new coding efforts were the integral packages (the MOLECULE package of J. Almlöf, the VPROP package of P.R. Taylor, and the integral derivative package ABACUS of T. Helgaker, P. Jorgensen J. Olsen, and H.J. Aa. Jensen). The latter was modified extensively for adaptation with Aces II, while the others remained very much in their original forms.
Ultimately, two different versions of the program evolved. The first was maintained by the Bartlett group at the University of Florida, and the other (known as ACESII-MAB) was maintained by groups at the University of Texas, Universitaet Mainz in Germany, and ELTE in Budapest, Hungary. The latter has recently been renamed as CFOUR.
Aces III is a parallel implementation that was released in the fall of 2008. The effort led to definition of a new architecture for scalable parallel software called the super instruction architecture. The design and creation of software is divided into two parts:
1. The algorithms are coded in a domain specific language called super instruction assembly language or SIAL, pronounced "sail" for easy communication.
2. The SIAL programs are executed by a MPMD parallel virtual machine called the super instruction processor or SIP.
The ACES III program consists of 580,000 lines of SIAL code of which 200,000 lines are comments, and 230,000 lines of C/C++ and Fortran of which 62,000 lines are comments.
Ab initio quantum chemistry methods
Ab initio quantum chemistry methods are computational chemistry methods based on quantum chemistry. The term ab initiowas first used in quantum chemistry by Robert Parr and coworkers, including David Craig in a semiempirical study on the excited states of benzene.The background is described by Parr...
computational chemistry
Computational chemistry
Computational chemistry is a branch of chemistry that uses principles of computer science to assist in solving chemical problems. It uses the results of theoretical chemistry, incorporated into efficient computer programs, to calculate the structures and properties of molecules and solids...
package for performing high-level quantum chemical ab initio calculations. Its major strength is the accurate calculation of atomic and molecular energies as well as properties using many-body techniques such as many-body perturbation theory (MBPT) and, in particular coupled cluster techniques to treat electron correlation. The development of ACES II began in early 1990 in the group of Professor Rodney J. Bartlett
Rodney J. Bartlett
Rodney J. Bartlett, born March 31, 1944 in Memphis, Tennessee, U.S., is Graduate Research Professor of Chemistry and Physics, University of Florida, Gainesville, USA. He received his B.Sc. degree from Millsaps College in 1966 and Ph.D. from the University of Florida in 1971. Bartlett was an NDEA...
at the Quantum Theory Project (QTP) of the University of Florida
University of Florida
The University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
in Gainesville. There, the need for more efficient codes had been realized and the idea of writing an entirely new program package emerged. During 1990 and 1991 John F. Stanton, Jürgen Gauss, and John D. Watts, all of them at that time postdoctoral researchers in the Bartlett group, supported by a few students, wrote the backbone of what is now known as the ACES II program package. The only parts which were not new coding efforts were the integral packages (the MOLECULE package of J. Almlöf, the VPROP package of P.R. Taylor, and the integral derivative package ABACUS of T. Helgaker, P. Jorgensen J. Olsen, and H.J. Aa. Jensen). The latter was modified extensively for adaptation with Aces II, while the others remained very much in their original forms.
Ultimately, two different versions of the program evolved. The first was maintained by the Bartlett group at the University of Florida, and the other (known as ACESII-MAB) was maintained by groups at the University of Texas, Universitaet Mainz in Germany, and ELTE in Budapest, Hungary. The latter has recently been renamed as CFOUR.
Aces III is a parallel implementation that was released in the fall of 2008. The effort led to definition of a new architecture for scalable parallel software called the super instruction architecture. The design and creation of software is divided into two parts:
1. The algorithms are coded in a domain specific language called super instruction assembly language or SIAL, pronounced "sail" for easy communication.
2. The SIAL programs are executed by a MPMD parallel virtual machine called the super instruction processor or SIP.
The ACES III program consists of 580,000 lines of SIAL code of which 200,000 lines are comments, and 230,000 lines of C/C++ and Fortran of which 62,000 lines are comments.
See also
- Quantum chemistry computer programsQuantum chemistry computer programsQuantum chemistry computer programs are used in computational chemistry to implement the methods of quantum chemistry. Most include the Hartree–Fock and some post-Hartree–Fock methods. They may also include density functional theory , molecular mechanics or semi-empirical quantum...