ggA

GGA is an acronym that can refer to several distinct concepts in science, technology, and government. In science and technology, GGA most commonly denotes Generalized Gradient Approximation, a class of exchange-correlation functionals used in density functional theory. These functionals incorporate the gradient of the electron density, improving upon the local density approximation. They are widely used in computational chemistry and condensed matter physics. Well-known GGA functionals include PBE (Perdew–Burke–Ernzerhof), PW91 (Perdew–Wang 1991), and revPBE. PBE, introduced in 1996 by Perdew, Burke, and Ernzerhof, became particularly influential due to its balance of accuracy and computational efficiency. While powerful, GGA functionals have limitations, such as imperfect treatment of van der Waals forces and sometimes overestimation of lattice constants in solids.

In biology, GGA refers to the codon GGA, one of the four codons that encode the amino acid glycine in the standard genetic code. The glycine codons are GGU, GGC, GGA, and GGG. During translation, these triplets are read by the ribosome, and tRNA deliver the corresponding amino acid. Codon usage can vary among organisms and contexts, but all four codons specify glycine.

In government, GGA may stand for the Georgia General Assembly, the state legislature of Georgia, United States. It is a bicameral body consisting of the Senate and the House of Representatives. The assembly meets in Atlanta and is responsible for enacting state laws, approving budgets, and confirming certain appointments, within the framework of the state constitution.