ELPASolver¶

class ELPASolver(bands_above_fermi_level=None, processes_per_kpoint=None, optimize_for_speed_over_memory=None)¶

Calculate the density matrix by direct diagonalization.

Parameters:

bands_above_fermi_level (int | Automatic | All) – The number of bands above the Fermi level. Must be either a non-negative integer, All or Automatic. When set to All the total number of bands will be equal to the total number of basis functions. When set to Automatic an adaptive method will be used. For most systems, Automatic provides a major speed-up as compared to All. If the number of states above the Fermi level changes significantly from one diagonalization step to another, the adapative method may lead to slowing down of the calculation.
Default: Automatic
processes_per_kpoint (int) – The number of processes to use per kpoint. Must be a positive integer.
Default: The number will be determined automatically from the total number of k-points and processes such as to keep the number as small as possible. One may set this number manually in order to reduce the memory requirements for each process.
optimize_for_speed_over_memory (bool) – Whether to optimize the diagonalization for speed over memory. If True, the solver will determine the most optimal algorithm in terms of speed. Note that optimizing for speed can increase the memory usage by up to 30 %. Note also that this flag only has an effect if processes_per_kpoint=1, or the automatic value for processes_per_kpoint=1 turns out to be 1. It is intended to be used for medium-sized to large systems with many k-points.
Default: False

bandsAboveFermiLevel()¶

optimizeForSpeedOverMemory()¶

Returns:: Whether the diagonalization should be optimized for speed over memory.
Return type:: bool

processesPerKpoint()¶

uniqueString()¶: Return a unique string representing the state of the object.

Notes¶