releases |

v1.10 — September 2025

Documentation Installers Source Release Notes Advertised Version: 1.10 Continuous Version: 1.10 Release Date: 5 Sep 2025 Documentation: https://psicode.org/psi4manual/1.10.x/ . Availability: Public, GitHub source, CMake build, Conda binary installers, Docker Span: 98 PRs Required Dependency Changes See External Libraries below for dependency bumps. QCManyBody is newly required. New Methods #3157 Added Python interface (Pybind) for building LS-THC quantities that allow for rapid prototyping of new methods involving THC. Developed infrastructure for the development of alternate ways to perform THC (i.

v1.9.1 — February 2024

Documentation Installers Source Release Notes Advertised Version: 1.9.1 Continuous Version: 1.9.1 Release Date: 8 February 2024 Documentation: https://psicode.org/psi4manual/1.9.x Availability: Public, GitHub source, CMake build, Conda binary installers, Docker Span: 5 PRs Conda Package Updates use pytest v7, as v8 is broken for psi4 #3107 prefer libint v2.8 (conda install libint -c conda-forge) over development (-c conda-forge/label/libint_dev) and psi4-stored builds #3103 refine libxc minimum to v6.1.0 Bug Fixes #3130 fixes symbols list for AM>=12 #3127 fixes import when $HOME directory is symlinked #3097 Fix Python3 compatibility in vmd_cube.

v1.9 — December 2023

Documentation Installers Source Release Notes Advertised Version: 1.9.0 Continuous Version: 1.9.0 Release Date: 6 Dec 2023 Documentation: https://psicode.org/psi4manual/1.9.x/ . Availability: Public, GitHub source, CMake build, Conda binary installers, Docker Span: 79 PRs Required Dependency Changes (3 PRs) #3022: Updates QCEngine to v0.28 #2968: Updates gdma to v2.3 and switches gdma usage to be selectable at runtime #3090: Updates QCFractal to v0.52 #2842 Bump Libxc minimum from v5.1.2 to v6 New Methods (6 PRs) #2992: Adds support for computation of analytic Hessians when using unrestricted DFT with LDA functionals #3039: adds fitted SAP guess described in J.

v1.8.2 — October 2023

Documentation Installers Source Release Notes Advertised Version: 1.8.2 Continuous Version: 1.8.2 Release Date: 3 October 2023 Documentation: https://psicode.org/psi4manual/1.8.x/ . Use #2965 for build documentation. Availability: Public, GitHub source, CMake build, DNE Conda binary installers, DNE Docker Span: 7 PRs Features #3019 still using pydantic v1 API, but now tolerant of a v1 or v2 pydantic environment. (this was already present by patch in build _2 of v1.8.1 on conda-forge.) #3039 adds fitted SAP guess described in J.

v1.8.1 — July 2023

Documentation Installers (DNE) Source Release Notes Advertised Version: 1.8.1 Continuous Version: 1.8.1 Release Date: 13 July 2023 Documentation: https://psicode.org/psi4manual/1.8.x/ . Use #2965 for build documentation. Availability: Public, GitHub source, CMake build, DNE Conda binary installers, DNE Docker Span: 7 PRs Conda Package Updates includes PCMSolver includes libECPInt (build _2 onwards; not present for osx-arm64 with py != 3.10 in build _1 or _0) includes files so psi4 --plugin-compile from Linux and Mac can work off the conda binary compatible with pydantic v1 or v2 in build _2 Bug Fixes #2963 fixes correctness bug in LPB routine with pyddx; now requires >= v0.

v1.8 — May 2023

Documentation Installers Source Release Notes Advertised Version: 1.8 Continuous Version: 1.8 Release Date: 11 May 2023 Documentation: https://psicode.org/psi4manual/1.8.x/ . Use https://github.com/psi4/psi4/issues/2965 for build documentation. Availability: Public, GitHub source, CMake build, Conda binary installers, Docker Span: 78 PRs Required Dependency Changes See External Libraries below for dependency bumps. Boost header-only libraries for compiling against Libint2. This isn’t a change to Psi4 or to Libint2; it’s just a change to how Libint2 was packaged.

v1.7 — December 2022

Documentation Installers Source Release Notes Advertised Version: 1.7 Continuous Version: 1.7 Release Date: 6 Dec 2022 NYI Documentation: https://psicode.org/psi4manual/1.7.0/ Availability: Public, GitHub source, CMake build, NYI Conda binary installers Span: 141 PRs Required Dependency Changes New Methods Hybrid perturbative methods REMP (https://doi.org/10.1063/1.5086168) and OO-REMP (https://doi.org/10.1021/acs.jctc.1c00280) with cc_type = CONV/DF/CD. REMP is essentially a hybrid between MP and CEPA(0) rewritten as perturbation theory (https://doi.org/10.1016/j.cplett.2006.07.081). REMP2 energies and OREMP2 energies and non-CD gradients are available.

v1.6.1 — July 2022

Documentation Installers Source Release Notes Advertised Version: 1.6.1 Continuous Version: 1.6.1 Release Date: 8 July 2022 Documentation: https://psicode.org/psi4manual/1.6.1/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 6 PRs Bug Fixes #2616 corrected syntax for spherical basis sets in Molden files. #2615 allows Psi4/Cfour interface to work again after distributed driver caused basis set detection and cbs QCVariable storage to break. #2595 allows Forte to work again after distributed driver interrupted options handling.

v1.6 — May 2022

Documentation Installers Source Release Notes Advertised Version: 1.6 Continuous Version: 1.6 Release Date: 19 May 2022 NYI Documentation: https://psicode.org/psi4manual/1.6.0/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 138 PRs Required Dependency Changes SciPy for ADIIS/EDIIS. Can be avoided. Python minimum bumped to v3.8. No longer need GMP/MPFR to build against Libint2. Better Eigen3, Boost transitive dependency handling. (#2413, #2046) Newer Libint2 required (interface change) and need new integrals classes.

v1.5 — November 2021

Documentation Installers Source Release Notes Advertised Version: 1.5 Continuous Version: 1.5 Release Date: 27 November 2021 Documentation: https://psicode.org/psi4manual/1.5.0/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 60 PRs, roughly 2247-2366 Obtaining Binary installers: see link above Python Anaconda: conda install psi4 -c psi4. Windows conda packages available (#1560) Dropped dependencies: none Added dependencies: none New Methods Domain-based local pair natural orbital MP2 implemented! Accessible through energy("dlpno-mp2") (#2093, #2313).

v1.4.1 — October 2021

Documentation Installers Source Release Notes Advertised Version: 1.4.1 Continuous Version: 1.4.1 Release Date: 7 October 2021 Documentation: https://psicode.org/psi4manual/1.4.0/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 3 PRs Bug Fixes #2283 largely fixes blatantly wrong SCF energies for omega functionals, especially with threading. Report any persisting discrepancies between set omega_combine true/false to #2279, please. #2273 allows the set scf_properties mbis_charges; energy("scf") route to MBIS charges to run again without failing for missing data.

v1.4 — August 2021

Documentation Installers Source Release Notes Advertised Version: 1.4 Continuous Version: 1.4 Release Date: 3 August 2021 Documentation: https://psicode.org/psi4manual/1.4.0/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 437 PRs, roughly 1559-2264 Obtaining Binary installers: see link above Python Anaconda: conda install psi4 -c psi4. Windows conda packages available (#1560) Dropped dependencies: deepdiff, Libint1 Added dependencies: QCEngine, Libint2 New Methods Add ability to call Axilrod-Teller-Muto (ATM) 3-body dispersion correction from Grimme’s DFTD3.

v1.3.2 — May 2019

Documentation Installers Source Release Notes Advertised Version: 1.3.2 Continuous Version: 1.3.2 Release Date: 17 May 2019 Documentation: http://psicode.org/psi4manual/1.3.2/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 3 PRs Enhancements #1576 regularize MP2 correlation QCSchema variable and move psi4 --json output to tmpfile. Building Bug Fixes #1602 fixes multiple bugs in NBOWriter that make all previous Psi-generated NBO files suspect. #1607 explicitly allow loading pickles in np.

v1.3.1 — April 2019

Documentation Installers Source Release Notes Advertised Version: 1.3.1 Continuous Version: 1.3.1 Release Date: 15 April 2019 Documentation: http://psicode.org/psi4manual/1.3.1/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 5 + 4 partial PRs Enhancements #1570 (partial) better format exception when run_json encounters error. set_options can be used for local options, e.g., set_options({'scf__d_convergence': 8}). #1578 (1st commit) update schema name to qcschema_[in|out]put, use dtype=2 Molecule in schema, move psi4:qcvars to extras/qcvars.

v1.3 — February 2019

Documentation Installers Source Release Notes Advertised Version: 1.3 Continuous Version: 1.3 Release Date: 28 February 2019 Documentation: http://psicode.org/psi4manual/1.3/ Availability: Public, GitHub source, CMake build, Conda binary installers Span: 335 PRs, roughly 1065-1558 Major Points of Interest Added native Windows compatibility without the WSL requirement. DFT collocation grids can now be cache in-memory to avoid extra computation and lowering the total cost of DFT by up to a factor of two (#1233).

v1.2 — July 2018

Documentation Installers Source Release Notes Advertised Version: 1.2 Continuous Version: 1.2 Release Date: 4 July 2018 Documentation: http://psicode.org/psi4manual/1.2/ Availability: Public, GitHub source, CMake build, Conda binary installers Major Points of Interest The DFT kernels were migrated to use LibXC, Psi4 now has 400+ functionals including modern functionals such as wB97M-V. The DFT code was optimized leading up to a 4x speed enhancement on 6 cores. A new Density-Fitted JK backend was written, DF-SCF is now up to 2x as fast.

v1.1 — May 2017

Documentation Installers Source Release Notes Advertised Version: 1.1 Continuous Version: 1.1 Release Date: 19 May 2017 Documentation: http://psicode.org/psi4manual/1.1/ Availability: Public, GitHub source, CMake build, Conda binary installers New Methods Added analytic RHF Hessians, conventional and density fitted. Added analytic RHF CCSD(T) gradients (no frozen core). Added functional-group and intramolecular symmetry-adapted perturbation theory (F/I-SAPT) capabilities, scripts, and tests. (DOIs: 10.1021/ct500724p, 10.1063/1.4927575) Added high-spin open-shell SAPT0. Note that Ind20,r (and exch counterpart) contains unrelaxed induction.

v1.0 — July 2016

Documentation Installers Source Release Notes Advertised Version: 1.0 Continuous Version: 1.0 Release Date: 4 Jul 2016 Documentation: http://psicode.org/psi4manual/1.0.0/ Availability: Public, GitHub source, CMake build, Conda binary installers Psi4is, in many ways, a whole new package compared to Psi3. While some libraries and modules remain the same, the majority of the code has been rewritten from scratch based on a powerful set of new libraries written in C++. A totally new Python front-end makes Psi4incredibly user-friendly and automates many common tasks such as basis set extrapolation, composite methods, running the same computation on every molecule in a test set, etc.

Beta5 — July 2013

Documentation Source Release Notes RN at GitHub link much better formatted than below. Advertised Version: 4.0b5 Continuous Version: 1.0b5 Release Date: 3 Jul 2013 Documentation: http://psicode.org/psi4manual/4.0b5/ Availability: Public, Sourceforge source, Autotools build, No binary This release adds a little additional functionality, fixes several bugs, improves the installation process and the documentation, and adds a couple of new built-in databases. It also includes some work-in-progress that will lead to improvements in the next release.

Beta4 — Apr 2013

Documentataion Source Release Notes Advertised Version: 4.0b4 Continuous Version: 1.0b4 Release Date: 7 Apr 2013 Documentation: http://psicode.org/psi4manual/4.0b4/ Availability: Public, Sourceforge source, Autotools build, No binary The first public beta release includes all-new, very efficient density-fitted, shared-memory parallel code for Hartree-Fock, DFT, and MP2, and symmetry-adapted perturbation theory (SAPT). We also add new code for MP4, QCISD(T), and G2. New modules performing frozen natural orbital coupled-cluster have been added. Previous PSI3 functionality for coupled-cluster energies and properties, and arbitrary-order CI and MBPT energies is also available.

Beta3 — Oct 2012

Documentation Source Release Notes Advertised Version: 4.0b3 Continuous Version: 1.0b3 Release Date: 23 Oct 2012 Documentation: http://psicode.org/psi4manual/4.0b3/ Availability: Private, No Sourceforge source, Autotools build, No binary This version of PSI contains the following features: Hartree-Fock, DFT, MP2, CI, CC, PSIMRCC, ADC(2), SAPT, DCFT, and optimized-orbital MP2 and MP3. Density-fitting is available for Hartree-Fock, DFT, MP2, and SAPT, and is much faster than the conventional algorithms. Most popular functionals are available, but only M05 and M05-2X are available among meta-GGA’s.

Beta2 — May 2012

Documentation Source Release Notes Advertised Version: 4.0b2 Continuous Version: 1.0b2 Release Date: 6 May 2012 Documentation: http://psicode.org/psi4manual/4.0b2/ Availability: Private, No Sourceforge source, Autotools build, No binary The Beta2 release fixes the following bugs reported by beta testers: Boost library compilation inside PSI4 now uses the user’s PYTHON environmental variable, to help avoid the situation where one version of Python is used for Boost, and another for PSI4, leading to linker errors.

Beta1 — Feb 2012

Source Release Notes Advertised Version: 4.0b1 Continuous Version: 1.0b1 Release Date: 2 Feb 2012 Documentation: None Availability: Private, No Sourceforge source, Autotools build, No binary