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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 Thus, users of the outdated PC GAMESS binaries (version 7.1.B and all earlier releases) were required to discontinue using the PC GAMESS and upgrade to Firefly.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.
Granovsky, Alexander A. (7 June 2011). "Extended multi-configuration quasi-degenerate perturbation theory: The new approach to multi-state multi-reference perturbation theory". The Journal of Chemical Physics. 134 (21): 214113. Bibcode:2011JChPh.134u4113G. doi:10.1063/1.3596699. PMID21663350.
