OpenQP v1.3.1

OpenQP v1.3.1

OQP Studio downloads: Studio 0.2.4 is now available from the independent Studio release repository. Visit the dedicated download page and release notes. Historical Studio 0.2.3 assets below remain available with unchanged files and URLs.

OpenQP v1.3.1 makes Windows a supported platform and adds analytic nuclear
gradients across the correlated-wavefunction stack. Everything from v1.3.0
still applies; this release adds to it rather than changing existing behaviour.

Highlights

• Windows is supported. pip install openqp now works on Windows, built
  with Intel oneAPI (ifx/icx) against MKL ILP64
  (#359), on top of
  Intel compiler support for every platform
  (#357).
• Analytic nuclear gradients for RHF MP2, state-specific CASSCF, SA-CASSCF,
  SC-NEVPT2, and CASPT2/XMS-CASPT2
  (#345,
  #346,
  #348,
  #349,
  #350).
• A DFT energy error, found while porting to Intel. Argument aliasing in
  the exchange-correlation density path made every DFT energy wrong by roughly
  0.07-0.25 Ha under ifx while GNU builds were unaffected
  (#357).

New features and scientific capabilities

• Analytic RHF MP2 nuclear gradients
  (#345).
• Analytic state-specific CASSCF nuclear gradients
  (#346) and
  analytic SA-CASSCF nuclear gradients
  (#348), replacing
  the central-difference route for these methods.
• Analytic strongly contracted NEVPT2 (SC-NEVPT2) nuclear gradients
  (#349).
• Analytic CASPT2 and XMS-CASPT2 nuclear gradients
  (#350).
• Numerical nuclear gradients for CASSCF and SA-CASSCF
  (#343), which
  remain available as a reference route for the analytic implementations above.

Bug fixes and reliability

• DFT exchange-correlation density: argument aliasing. calc_dft_xc_density
  passed the same array as two distinct dummy arguments. Under ifx the
  copy-out of the untouched second temporary zeroed the XC Fock contribution,
  leaving every DFT energy 0.07-0.25 Ha off while E_xc itself looked exact.
  GNU builds happened to alias in a way that hid it
  (#357).
• Nine further latent defects surfaced by a second compiler: an unallocated
  pivot array used before a workspace query, calls through a null pfon
  pointer, .TRUE. reaching Python as 255, and intermittent forrtl 184
  aborts from polymorphic intrinsic assignment
  (#357).
• Huckel guesses with zero beta electrons now initialize and stay within
  orbital bounds (#342).
• PT2 route ownership is decided inside the route rather than at each call site
  (#356).
• The log banner now prints the real version. It said "Version: 1.0 Aug,
  2024" for two years of releases because nothing tied it to the build; it now
  derives from CMake's project version, which the release-metadata test keeps
  in sync with pyproject.toml, and a test forbids a literal version from
  reappearing (#365).
• Recorded the measurement showing the MRSF ROHF Davidson trial-vector diagonal
  is correct as shipped, closing
  #328
  (#351).

Packaging, platforms, and CI

• Windows wheels for CPython 3.9-3.14 on x86-64
  (#359). They link
  MKL ILP64 but do not carry it: a single MKL library exceeds PyPI's per-file
  limit, so mkl is a runtime dependency, pinned to the oneAPI series the
  wheels are compiled against. Installing therefore pulls in mkl and
  intel-openmp.
• Intel oneAPI is a supported toolchain on every platform
  (#357).
• Windows source builds require the Intel compilers, Visual Studio Build
  Tools, and a single-configuration generator. Static builds, multi-config
  generators, and ENABLE_DDX are rejected during configuration with an
  explanation rather than failing later
  (#359).
• macOS wheels build again with delocate 0.13, which rewrites @rpath
  entries to explicit @loader_path and drops the now-unused LC_RPATH. The
  wheel gate accepted only the older layout and would have blocked macOS wheels
  from this release
  (#360).
• .oqp inputs render on one line, with options that merely restate runtime
  defaults dropped
  (#358).
• Tight-binding material was removed from the public repository
  (#354).
• Line endings are pinned to LF via .gitattributes. Windows checks out
  with core.autocrlf enabled by default, which rewrote LF to CRLF and made
  the Windows wheels ship license text that no longer matched the tagged
  source. The repository was already entirely LF, so no tracked file changed --
  only the guarantee that a checkout is byte-identical on every machine
  (#364).

Compatibility notes

• LP64 is gone. OpenQP uses one 8-byte BLAS/LAPACK integer model on every
  platform. -DLINALG_LIB_INT64=OFF now fails the configure deliberately, so a
  stale CMake cache cannot produce a mixed-width build. macOS reaches ILP64
  through Accelerate's $NEWLAPACK$ILP64 interface and therefore requires
  macOS 13.3 or newer.
• Windows is x86-64 only. There is no native Windows-on-ARM wheel, and the
  source route does not target it either.

Documentation and developer experience

• Standardized OpenQP theory log output, and added Alireza as an author
  (#347).
• Corrected the README claim that SA-CASSCF gradients used central differences
  (#355).
• Corrected the v1.3.0 notes and the OCI attestation verification steps
  (#341).

Contributors

• Cheol Ho Choi

Known limitations

• C2H4_BHHLYP-MRSFTDDFT_MEP aborts intermittently with forrtl 184 under
  Intel builds. The polymorphic-assignment sites found during the port were
  fixed, and a 96-run stress pass was clean, but the failure has recurred once
  since; it is not specific to any change in this release.

Full changelog: v1.3.0...v1.3.1

Downloads: OpenQP engine and historical Studio 0.2.3

The attached openqp-1.3.1-* files are self-contained command-line OpenQP
engines for macOS, Linux, and Windows.

The OQP Studio 0.2.3 files are retained here as historical downloads so
existing links continue to work:

• OQP-Studio-0.2.3-*: the standard desktop application for use with a
  separately installed engine;
• OQP-Studio-0.2.3-*-with-engine*: the integrated desktop application with
  OpenQP 1.3.1 bundled for offline calculation.

For Studio downloads, use the dedicated download page.
See the Studio release notes
and installation guide.

Starting with Studio 0.2.4, new installers will be published separately in
the planned public Open-Quantum-Platform/oqp-studio-releases repository,
rather than attached to OpenQP engine releases. Studio and engine versions are
independent. Studio 0.2.4 has not been released yet; the dedicated download
page currently links to the historical 0.2.3 installers.

Use the existing SHA256SUMS asset to verify downloads from this release.