• giannozz's avatar
    Treatment of fractional translations significantly changed. Before: · caf21dd3
    giannozz authored
    - operations with fractional translations were discarded if not commensurate
      with FFT grid (unless input variable "use_all_frac" was set to true)
    
    Now:
    - FFT grids are made commensurate with fractional translations
      (unless use_all_frac is set to true)
    
    Advantages:
    - the number of k-points and of symmetry operations no longer depends upon the
      cutoff via the FFT grid (could happen, and did happen, before)
    - cleaner code, allowing easier automatic parallelization over k-points
    Disadvantage:
    - the FFT grid may become slightly larger
    
    Changes are minimal because the machinery was already in place (see variable
    "fft_fact" that contains factors for FFT dimensions). Cleanup: useless calls
    to fft_type_allocate removed (it is called by fft_init_type anyway).
    Documentation and examples updated. The usage of "use_all_frac" is a little
    bit weird, though (should be the other way round).
    caf21dd3
fft_types.f90 41.8 KB