For questions please use the QMCPACK Google Group.

A list of releases made from GitHub can be browsed at Source code, including for the current development version, is available at

The latest nightly test status can be browsed at

QMCPACK Release v3.10.0 - 2020-11-10

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This release contains multiple feature improvements and bug fixes. The AFQMC implementation has been significantly enhanced, and an important wavefunction optimization bug fixed in real space QMC.

  • The QMCPACK manual is now available at, having been converted to use reStructuredText and the sphinx documentation system.
  • Significant improvements to the AFQMC code including HIP support for AMD GPUs, updated documentation, and support for non-collinear calculations and spin-orbit k-point Hamiltonians #2734.
  • Improved support for spin-orbit in real-space QMC including documentation #2733.
  • Important bug fix for wavefunction optimization in few electron systems such as isolated atoms. The bug would result in slow or no convergence. Thanks to Jaron Krogel and Matus Dubecky for reports and reproducers. #2496.
  • Implementation of L2 potentials and evaluation in DMC #1948.
  • Consistent with our two year support policy for open source compilers, libraries, and tooling, several version minimums have been increased to either avoid bugs or to utilize new features.
  • Clang 7 is the earliest supported Clang compiler. The latest release is recommended.
  • Intel 2019 is the earliest supported Intel compiler. The latest release is recommended.
  • Future releases of QMCPACK will require C++17. The current minimum is C++14.
  • AoS builds are no longer supported. The code has been removed now that the default structures-of-arrays (SoA) build has sufficiently broad capability.
  • The default CUDA architecture is set to sm_70 (Volta).
  • QMCPACK is built with ENABLE_TIMERS=ON by default #2663
  • Various bug fixes to complete the transition to Python 3.
  • Ongoing improvements to the OpenMP offload implementation.


  • NEXUS manual is now available at, having been converted to use the reStructuredText and sphinx documentation system.
  • Various small fixes and improvements.

QMCPACK Release v3.9.2 - 2020-04-29

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This is an important bug fix release. As described in GitHub issue #2330, since v3.8.0 the timestep was not correctly changed between different DMC blocks if the time step was changed in the input, biasing the results. Runs using a single time step were not affected. Thanks to Chandler Bennett for identifying the problem.

  • Bug fix: timestep was not correctly changed between DMC blocks if it was changed in the input #2330.
  • qmcfinitesize tool added #2329.
  • QMCPACK spack package now supports AFQMC #2237.
  • Improvements to deterministic tests: these are now fully reliable other than for some CUDA builds and some mixed precision CPU configurations.
  • Many improvements to cmake configuration for faster builds, e.g. #2389.
  • Ongoing source cleanup and fewer compile-time warnings, e.g. #2375.

QMCPACK Release v3.9.0 - 2020-02-11

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This release includes a large number of refinements to improve or extend the functionality of QMCPACK and NEXUS. Importantly, this release supports and requires Python 3. After this release we plan to remove the array-of-structures build configuration and also the legacy CUDA implementation for GPUs. If any needed functionality is not supported by the now-default structures-of-arrays configuration, users should contact the developers via the QMCPACK Google Groups or via an issue on the QMCPACK GitHub repository. Work is ongoing to support dynamical spin variables, implement spin-orbit, and to develop new support for accelerators via a new framework that will consistently support CPUs and GPUs from the same codebase.

  • All uses of Python updated to Python 3, which is now required. Python 2 was retired at the end of 2019, and many packages already only support Python 3.
  • A greatly expanded selection of effective core potentials is available at in formats suitable for QMCPACK and common DFT and quantum chemistry codes.
  • All major functionality is now supported by the default structures-of-arrays (SoA) build. This release is the last to support the legacy array-of-structures (AoS) build. See #861.
  • Major bug identified and fixed in the periodic Coulomb evaluation (Optimized breakup method of Natoli-Ceperley). Many thanks to Jan Brndiar and coworkers for reporting this. For large anisotropic supercells such as a graphene layer with substantial vacuum, the ion-ion potential was incorrectly computed. Results in all bulk-like supercells tested so far have been accurate. An independent Ewald check of the ion-ion potential evaluation has been added. See #2137. The Coulomb potential evaluation has also been found to converge very slowly for certain anisotropic supercells, particularly for quasi-2D cells where huge errors can result. The new independent Coulomb check will abort if a tolerance is not reached and provide guidance. Research is ongoing to develop an improved methodology #2185.
  • Support for periodic gaussian-based trial wavefunctions at complex k-points #1988.
  • Determinant-localization approximation (DLA) of Zen et al. J. Chem. Phys. 151, 134105 (2019) for DMC non-local pseudopotential evaluation implemented.
  • Improved force implementation #1769#1768.
  • Non-local pseudopotential derivatives are supported in the SoA build and recommended for all optimizations #2083.
  • Above 192 electrons in a spin determinant, delayed updating with delay 32 is enabled by default for higher performance, #2027. Rank-1 updating is used by default for smaller determinants.
  • Improved configuration and detection of Intel MKL and vector MKL when used with non-Intel compilers.
  • QMCPACK will now run with wavefunctions where only electrons of a single spin are specified. #2148.
  • AFQMC estimators now include 1 and 2 body reduced density matrices (1RRM, 2RDM) and on-top pair density. #2097.
  • Dense real hamiltonian added for AFQMC allowing for GPU acceleration for chemistry applications. #2131.
  • QMCPACK spack package supports the latest release as well as the development version. This package can also install and patch Quantum Espresso.
  • Support for Blue Gene removed due to retirement of this architecture.
  • Many minor bug fixes, expanded testing, and small feature improvements.

Known bugs

See list of open bugs.

  • Use of reconfiguration in DMC is disabled since it is incorrect. #2254


  • NEXUS version is increased to 2.0.0 due to major updates in this release.
  • NEXUS has been transitioned to Python 3 and now requires it.
  • Significantly expanded test system to cover all major functionality.
  • Full support for PySCF to QMCPACK and AFQMC workflows #1970.
  • Support for DLA #2061.
  • VMC optimization performed with NLPP derivatives by default #2128.
  • Many minor bugfixes and feature improvements.

QMCPACK Release v3.8.0 - 2019-07-23

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This release includes Quantum Espresso v6.4.1 support, new examples for adding wavefunctions and Jastrow functions, and many updates to the AFQMC code functionality. Additionally, all the updated scripts and functionality utilized during the 2019 QMCPACK workshop are provided; this link also includes several new tutorials. A large number of feature refinements, bugfixes, testing improvements and source code cleanup have also been performed.

  • Quantum Espresso v6.4.1 support #1732.
  • New tutorial for adding a simple wavefunction (He) #1621.
  • New tutorial and capability for adding Jastrow functors from symbolic expressions written in Python #1557.
  • Updated compiler and library support policy, and matching testing. We aim to support open source compilers and libraries within two years of release. Use of older software is discouraged and untested. Support for closed source compilers over the same period may require use of an exact version.
  • Many updates to AFQMC code to support more compilers and libraries.
  • Newly expanded deterministic test set should now pass on all platforms and be usable as an. installation check. Recommend to run "ctest -L deterministic" after building QMCPACK.
  • AFQMC code now only reads HDF5 format data to improve I/O performance and storage utilization.
  • K-point AFQMC code usable in production (e.g. bug fix #1524).
  • Updated AFQMC workflow scripts for interfacing with PySCF.
  • Faster initial cusp correction calculation for all-electron calculations, e.g. #1643.
  • Improved stability of cusp correction calculation #1594.
  • New short-ranged e-n Jastrow #1680.
  • Substantially faster 1-body reduced density matrix (1DRDM) estimator #1672.
  • Performance tests added for LCAO code and Gaussian basis sets #1639.
  • Reduced configuration output by default. Use -DQMC_VERBOSE_CONFIGURATION=1 on CMake line for greater detail.
  • Partial support for forces in LCAO basis e.g. #1559. See details given at 2019 QMCPACK Workshop and in manual.
  • Improved human-readable Jastrow output #1525.
  • Improved MPI implementation. QMCPACK is now compatible with OpenMPI v4.
  • Majority of the manual has been professionally edited.

Known bugs

See list of open bugs.

  • There is a general problem with MVAPICH2 involving aligned memory allocations that will cause QMCPACK to crash if MVAPICH is compiled using defaults. See #1703 for details and workaround.


  • Examples added of PySCF molecular and solid-state workflows #1552.
  • Update support for Quantum Package 2.0 #1538.
  • Support for additional machines including SuperMUC-NG #1665.
  • Support for ghost atoms #1653.
  • Update outdated cubic specifier to alat for QE #1642.
  • K-point grids are symmetrized with spglib #1544.
  • Bundling of jobs at NERSC #1748.