« PSI3: An Open-Source Ab Initio Electronic Structure Package, » T. Daniel Crawford, C. David Sherrill, Edward F. Valeev, Justin T. Fermann, Rollin A. King, Matthew L. Leininger, Shawn T. Brown, Curtis L. Janssen, Edward T. Seidl, Joseph P. Kenny, and Wesley D. Allen, J. Comp. Chem. 28, 1610-1616 (2007). (doi:10.1002/jcc.20573)
PSI is an ab initio computational chemistry package originally written by the research group of Henry F. Schaefer, III (University of Georgia). It performs high-accuracy quantum computations on small to medium-sized molecules.
PSI3 is the latest release of the program package.
The basic capabilities of PSI are concentrated around the following methods of quantum chemistry:
Package highlights include:
- Arbitrarily high angular momentum levels in integrals and derivative integrals. (Up to m-type functions have been tested.)
- Coupled cluster methods including CC2, CCSD, CCSD(T), and CC3 with RHF, ROHF, UHF, and Brueckner orbitals.
- Determinant-based CI including CASSCF, RAS-CI, and Full CI.
- Multithreaded integral-direct SCF, MP2, and MP2-R12.
- Excited state methods: CIS, CIS(D), RPA, EOM-CCSD, and CC3.
- Analytic energy gradients for CCSD with RHF, ROHF, and UHF orbitals.
- Coupled cluster linear response methods for static and dynamic polarizabilities and optical rotation.
- Diagonal Born-Oppenheimer correction (DBOC) for RHF, ROHF, UHF, and CI wave functions.
Available Platforms for PSI3
All PSI3 downloads are handled by Sourceforge.
PSI3 is designed for use on any UNIX-like system. The latest official release has been tested in the following environments:
- Linux on x86, x86_64, IA64 (Itanium2), and PPC
- Mac OS X (Darwin) on PPC (G4 and G5) and Intel processors (MacPro)
- SGI Altix
- IBM AIX 5.x on PPC
For more information on prerequisites and how to compile PSI3 refer to the installation manual.