OpenMC 0.6.1

New Features Coarse mesh finite difference (CMFD) acceleration no longer requires PETSc Statepoint file numbering is now zero-padded Python scripts now compatible with Python 2 or 3 Ability to run particle restarts in fixed source calculations Capability to filter box source by fissionable materials Nuclide/element names are now case insensitive in input files Improved treatment of resonance scattering for heavy nuclides Bug Fixes Check for energy-dependent multiplicities in ACE files Fix distance-to-surface calculation for general plane surface Account for differences in URR band probabilities at different energies Allow zero atom/weight percents in materials Don't use PWD environment variable when setting path to input files Handle probability table resampling correctly Fix metastables nuclides in NNDC cross_sections.xml file Don't read tallies.xml when OpenMC is run in plotting mode Prevent segmentation fault on "current" score without mesh filter Check for negative values in probability tables Ensure installation of Python modules goes into correct directory Contributors This release contains new contributions from the following people: @bhermanmit @nelsonag @paulromano @smharper @walshjon @wbinvento