Scientists at the Department of Energy's Ames Laboratory, led by Mark Gordon, director of the laboratory's Applied Mathematics and Computational Sciences Program, are fostering and expanding a computational chemistry code that provides extensive and detailed information about how things work on the molecular scale.
The General Atomic and Molecular Electronic Structure System, or GAMESS, includes a hierarchy of quantum chemistry methods that helps solve problems relating to molecules. Using GAMESS, the Gordon group is making major contributions to the design of new rocket fuels for the Air Force and new optical materials, fuels and wear-resistant coatings for the Department of Defense.
GAMESS is a "legacy" code that was assembled in 1977 from existing quantum chemistry computer programs by the staff at the National Resource for Computations in Chemistry.
The project ended in 1981, but the Gordon group has continued to enhance the software suite over the years, developing new functionalities and parallelizing the code. The researchers have created sophisticated and complex methods for GAMESS to address intermediates, unusual chemical species that may have lifetimes of only picoseconds or femtoseconds, but may be very important in the overall chemical reaction.
In addition, GAMESS includes the novel graphics visualization programs, MacMolPlt and WinMolPlt, for Macintosh computers and PCs, respectively. The programs ease the task of interpreting the complicated calculations performed by GAMESS.
A unique feature of GAMESS is the effective fragment potential, or EFP, which is based on quantum mechanics but is not quantum mechanics. The EFP is a sophisticated model to predict how solvents affect chemical reactions and to predict the behavior of liquids. Treating a molecular system with EFPs makes it possible to complete an entire calculation in orders of magnitude less computer time than a fully quantum calculation. "GAMESS runs on every kind of computer platform and compiler you can imagine," said Gordon. "It just passed 20,000 registered user groups in over 100 countries. This translates into an estimated 100,000 to 150,000 individual users. They range from people in academics to industry to government labs." GAMESS is distributed at no cost to users by accessing www.msg.ameslab.gov and signing a license agreement.
