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 v3.4.0 - 2018-01-29

Download QMCPACK v3.4.0


This release includes size-consistent t-moves, and improvements to load balancing and memory usage that will be visible in large runs. Significant revisions have been made to the gaussian wavefunction reader and a PySCF interface is in progress. A bug affecting non-git installs (from release tarballs) is fixed. Feedback is particularly welcome on the new features.

  • Size consistent t-moves implemented (Casula 2010 algorithm). Enabled via nonlocalmoves parameter, see manual.
  • Bugfix: For non-git builds, build process failed on some systems due to git-rev.h handling.
  • Optimized load balancing in DMC. Command line option async_swap removed. Parameter use_nonblocking now disables non-blocking MPI load balancing. Non-blocking MPI is now enabled by default.
  • Improved memory handling and usage in SoA code, increases performance.
  • Improved stability of GPU matrix inversion for large runs.
  • Ongoing improvements to output to improve readability.
  • Initial interface to PySCF for real space QMC trial wavefunctions.
  • Enabled use of HDF5 files for Gaussian based wavefunctions with SoA implementation.
  • Added Appendix to manual listing all known QMCPACK publications. This will be updated on an ongoing basis. Please advise of any missing publications.
  • Optimized momentum distribution estimator. Supported by SoA and 1,2,3-body Jastrow functions.
  • Support for labeled timers in Intel VTune based profiling.


  • Minor bugfixes and improvements.

Known limitations

  • PySCF interface is preliminary. convert4qmc is updated, but manual entries are not yet provided. This will be improved in later versions. The interface is currently only for isolated molecular systems. A full periodic implementation is in progress.

  • Documentation, examples and tutorials are not yet consistent with the updated converter convert4qmc.

QMCPACK Release v3.3.0 - 2017-12-17

Download QMCPACK v3.3.0


This release includes new methods, converter updates, and many optimizations, feature improvements, and bug fixes. It is a recommended update for all users.

QMCPACK updates

  • Support for finite difference linear response (FDLR) method and wavefunctions, developed and contributed by Nick Blunt and Eric Neuscamman, see Journal of Chemical Physics 147, 194101 (2017), and .
  • Major update to convert4qmc, conversion from GAMESS and other gaussian basis set codes. HDF5 output is now supported for large wavefunctions with -hdf5 option. Significantly improved example inputs *
  • Gaussian based trial wavefunctions now supported by structure of arrays implementation (ENABLE_SOA=1). A full reimplementation that will also support gaussians in periodic boundary conditions, e.g. from pyscf, is in progress.
  • Initialization of multideterminant wavefunctions improved for faster startup and lower memory usage. In practice this significantly raises the usable maximum number of determinants.
  • Maximum CPU time setting (maxcpusecs): QMC drivers will not start a new block if there is not enough estimated time remaining to complete the next block and gracefully shut down.
  • Homogeneous electron gas wavefunction support and tests.
  • New command line verbosity command line flag -verbosity. Output of QMCPACK will be overhauled over the next few releases to support low, high, and debug options, and also to significantly improve readability and utility.
  • Bugfix: Umrigar drift diffusion term is now consistent with the Umrigar small time step error algorithm with complex wavefunctions.
  • Bugfix: Momentum distribution is now correctly weighted and also correctly signed for twist averaging.
  • Renamed performance tests with atom and electron count.
  • Removed support for "buffering" of non-local pseudopotential wavefunction components during optimization (useBuffer setting) to reduce memory usage and for simplicity.
  • doxygen documentation for developer-level documentation of the code and file structure. Produced via make in qmcpack/doxygen. HTML currently published at
  • Many minor bug fixes and improved tests.


  • Improved postprocessing support for Quantum Espresso.
  • Various minor bug fixes.

Known issues and limitations

  • Documentation, examples and tutorials are not yet consistent with the updated converter convert4qmc.
  • Core functionality is largely compatible with ENABLE_SOA but some specialized wavefunctions and observables are not.
  • Use of GNU compilers with glibc 2.23 builds will crash due to a bug in libmvec of glibc. The glibc version can be verified by "ldd --version".

QMCPACK Release v3.2.0 – 2017-09-21


This release provides a significant speed increase for many calculations. A C++11 compiler is now required. It is a recommended update.

QMCPACK updates

  • Major speedup for calculations using spline wavefunctions via initial implementation of “Structure of Arrays” data layout and improved algorithms. Enabled via -DENABLE_SOA=1. Benefits all CPU architectures. Many runs are doubled in speed. Not yet available for Gaussian-basis sets or for all observables and QMC methods. See writeup in manual for guidance.
  • A compiler supporting C++11 is now required.
  • DMC respects MaxCPUSecs parameter and will gracefully shut down and not start a new block if there is not sufficient estimated time to complete it.
  • Checkpointing code rewritten for robustness and performance at scale. Parallel as well as serial HDF5 supported and autodetected.
  • Improved beta-release of AFQMC code and documentation.
  • Backflow documentation and optimization tips added.
  • Correlated sampling VMC drivers reactivated.
  • Added carbon graphite performance test similar to CORAL benchmark.
  • Improvements to CMake and CTest usage.
  • Build instructions for NERSC, ALCF, and OLCF machines updated.
  • Latest manual PDF now available here


  • Significantly improved manual entry for “qmca” analysis tool, the main recommended tool for statistical analysis of QMCPACK data.
  • Added time step fitting tool “qfit” for timestep extrapolation. Uses jack-knife statistical technique.
  • Improved density file postprocessing.
  • Support for Makov-Payne corrections.

QMCPACK Release v3.1.1 – 2017-08-01


This is a bugfix release and recommended update.

QMCPACK updates

  • Added numerical tolerance to check of jastrow cutoff and Wigner Seitz radius.
  • CMake correctly configures when MPI is not present.
  • Improved support for test coverage measurements.
  • Added unit tests for some estimators.


  • IPython compatible exit handling (from Duy Le)

QMCPACK Release v3.1.0 – 2017-06-21


This release incorporates an improved DMC equilibration scheme, numerous bugfixes, small improvements, and significantly improved testing. It is a recommended update.

QMCPACK updates

  • Improved population control during DMC equilibration. Reduces variance on larger runs.
  • Bugfix: Real valued wavefunction GPU code gave incorrect result for some non-gamma twists that could be made real, e.g. X point. Complex code (QMC_COMPLEX=1) was always correct.
  • All particle move VMC and DMC algorithms enabled, tests added.
  • Reptation Monte Carlo (RMC) enabled, tests added.
  • Significantly improved AFQMC implementation.
  • Added NiO based VMC and DMC performance tests and description in manual. Wavefunction files accessed via QMC_DATA.
  • Added DMC tests with locality and t-moves approximations.
  • Added AFQMC tests.
  • Added test of real space QMC restart capabilities.
  • Added tests for several estimators.
  • Added unit test for DMC walker propagation, effective core potentials, and OhmmsPETE.
  • To avoid filesystem limitations, QMC_SYMLINK_TEST_FILES can be set to symlink (1) or copy test files (0).
  • Fixed mixed precision Ceperley force evaluation.
  • Many updated tests to improve statistical reliability. Removed flux estimator from short tests because they were not reliable enough.
  • Tests that rely on non-standard python modules that are not available are skipped.
  • Error trap jastrow factors with cutoff radii larger than Wigner Seitz radius.
  • Bugfix: Prevent users from adding correlation terms on non-existing electron pairs, e.g. up-down correlation terms when only up-spin particles are present.
  • Support for measuring test coverage and performing coverage runs with cmake and ctest.
  • Support for GCC7 and IBM XL (non Blue Gene) compiler.
  • Support selecting GPU microarchitecture via -DCUDA_ARCH=sm_35(default).
  • SummitDev IBM Minsky build recipe (Power8 + NVIDIA Pascal P100 GPUs).
  • Significantly updated optimizer description in manual, including excited state optimization.
  • Added description of using Intel MKL with non-Intel compilers in manual.
  • Added description of MPIEXEC and MPIEXEC_NUMPROCS_FLAG to manual for systems where MPI runner is non-standard.
  • Updated labs with correct pseudopotentials, basis set files.
  • Many updated error messages and warnings.

Known problems

  • AFQMC without MKL will fail, e.g. short-afqmc-N2_vdz-4-1 test fails.

NEXUS updates

  • Improved selection algorithm to obtain optimally tiled supercells.
  • Support for parallel pw2qmcpack workflows.
  • Support for HPC resources at the Leibniz Supercomputing Center.
  • Better consistency checks for the Structure class.
  • Bugfix: forbid job bundling for simulations that depend on each other.
  • Bugfix: correctly select low spin polarization in primitive and tiled (net_spin=”low” option).