Firefly, formerly named PC GAMESS, is an

ab initio ''Ab initio'' ( ) is a Latin term meaning "from the beginning" and is derived from the Latin ''ab'' ("from") + ''initio'', ablative singular of ''initium'' ("beginning"). Etymology Circa 1600, from Latin, literally "from the beginning", from ab ...

computational chemistry Computational chemistry is a branch of chemistry that uses computer simulation to assist in solving chemical problems. It uses methods of theoretical chemistry, incorporated into computer programs, to calculate the structures and properties of m ...

program for

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

-compatible

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...

x86-64 x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit version of the x86 instruction set, first released in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mod ...

processor Processor may refer to: Computing Hardware * Processor (computing) **Central processing unit (CPU), the hardware within a computer that executes a program *** Microprocessor, a central processing unit contained on a single integrated circuit (I ...

s based on

GAMESS (US) General Atomic and Molecular Electronic Structure System (GAMESS (US)) is computer software for computational chemistry program. The original code started on October 1, 1977 as a National Resources for Computations in Chemistry project. In 1981, t ...

sources. However, it has been mostly rewritten (60-70% of the code), especially in platform-specific parts (

memory allocation Memory management is a form of Resource management (computing), resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their re ...

, disk

input/output In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...

network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

mathematic Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

functions (e.g.,

matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...

operations), and

quantum chemistry Quantum chemistry, also called molecular quantum mechanics, is a branch of physical chemistry focused on the application of quantum mechanics to chemical systems, particularly towards the quantum-mechanical calculation of electronic contributions ...

methods (such as

Hartree–Fock method In computational physics and chemistry, the Hartree–Fock (HF) method is a method of approximation for the determination of the wave function and the energy of a quantum many-body system in a stationary state. The Hartree–Fock method often a ...

Møller–Plesset perturbation theory Møller–Plesset perturbation theory (MP) is one of several quantum chemistry post–Hartree–Fock ab initio methods in the field of computational chemistry. It improves on the Hartree–Fock method by adding electron correlation effects by m ...

, and

density functional theory Density-functional theory (DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (or nuclear structure) (principally the ground state) of many-body ...

). Thus, it is significantly faster than the original GAMESS. The main maintainer of the program was Alex Granovsky. Since October 2008, the project is no longer associated with

and the Firefly rename occurred. Until October 17, 2009, both names could be used, but thereafter, the package should be referred to as Firefly exclusively.Firefly Home Page
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History

On December 4, 2009, the support of any PC GAMESS versions earlier than the first PC GAMESS Firefly version 7.1.C was abandoned, and any and all licenses to use the code were revoked. Thus, users of the outdated PC GAMESS binaries (version 7.1.B and all earlier releases) were required to discontinue using the PC GAMESS and upgrade to Firefly. On July 25, 2012, a state of the art edition of Firefly, version 8.0.0 RC, was launched for public beta testing. A relative comparison has shown that it is far faster and more reliable than the prior edition, Firefly 7.1.G. Many changes were made to enhance its abilities. In the Quantum Chemistry Speed Test, Firefly's DFT code came second (losing only to commercial QChem), beating other free DFT codes by a large margin. Firefly's unique capabilities include XMCQDPT2, a reformulation of Nakano's multi-state multi-configuration quasi-degenerate perturbation theory (MCQDPT) correcting for some of its deficiencies. At the end of 2019, Firefly's main developer A. A. Granovsky unexpectedly died but the project continues.
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References

External links

*
PC GAMESS SCF Benchmark
Computational chemistry software {{science-software-stub

History

See also

References

External links