PSI4 Coming Soon!
November 15, 2011. For more than two years, the PSI developers have been hard at work on The PSI4 Project. PSI4 features a completely rewritten set of libraries, a completely new SCF and DFT code (utilizing density fitting), an extremely efficient SAPT code, and more. We can routinely perform computations with more than 2500 basis functions running serially or in parallel. A powerful new PSI driver automates even complicated tasks with ease. We are adding shared-memory and distributed-memory parallel algorithms, and some parts of the code are being adapted to utilize graphical processing units (GPUs).
Some recent PSI4 news:
  • A preview of the PSI4 code and its capabilities has been published online in Wiley Interdisciplinary Reviews: Computational Molecular Science (DOI: 10.1002/wcms.93)
  • Our very fast SAPT0 code for analysis of intermolecular interactions has been published in a paper in the Journal of Chemical Physics (DOI: 10.1063/1.3656681)
Please stay tuned for further announcements.

Currently available version: The PSI3 suite of quantum chemical programs is designed for efficient, high-accuracy calculations of properties of small to medium-sized molecules. The package's current capabilities include a variety of Hartree-Fock, coupled cluster, complete-active-space self-consistent-field, and multi-reference configuration interaction models. Molecular point-group symmetry is utilized throughout to maximize efficiency. Non-standard computations are possible using a customizable input format. 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.
The latest version of the PSI package is psi-3.4.0 ("Xander"), which was released on 16 February 2009.
Primary development on PSI has been carried out by:
T. Daniel Crawford (Virginia Tech) C. David Sherrill (Georgia Tech)
Edward F. Valeev (Virginia Tech) Rollin A. King (Bethel University)

The development of PSI has been supported in part by the U.S. National Science Foundation under Awards CHE-0133174 (TDC), CHE-0715185 (TDC), CHE-0094088 (CDS) and the U.S. Department of Energy under lab-directed research and development grants from Sandia National Laboratories and Oak Ridge National Laboratory.
If you have comments, questions, or suggestions, email the developers at psicode@users.sourceforge.net.

This page was last updated on 11 June 2011.