abinslib.bose
=============

.. py:module:: abinslib.bose

.. autoapi-nested-parse::

   Bose occupation enum and calculations.



Exceptions
----------

.. autoapisummary::

   abinslib.bose.NegativeTemperatureError


Classes
-------

.. autoapisummary::

   abinslib.bose.BoseOccupation


Functions
---------

.. autoapisummary::

   abinslib.bose.calculate_bose_factor


Module Contents
---------------

.. py:exception:: NegativeTemperatureError

   Bases: :py:obj:`ValueError`


   Bose factor is not meaningful for negative temperature.


.. py:class:: BoseOccupation

   Bases: :py:obj:`enum.Enum`


   Occupation number for Bose-Einstein statistics.

   Typically we use 2N+1 in Debye-Waller factor (i.e. atomic displacements),
   N+1 for energy transfer to the sample and N for energy transfer from the
   sample.

   ONE is simply 1: i.e. unscaled temperature-insensitive occupation


   .. py:attribute:: ONE


   .. py:attribute:: N


   .. py:attribute:: N_PLUS_ONE


   .. py:attribute:: TWO_N_PLUS_ONE


.. py:function:: calculate_bose_factor(frequencies: euphonic.Quantity, temperature: euphonic.Quantity, occupation: BoseOccupation) -> numpy.array

   Get Bose factors corresponding to an array of frequency or energy.

   :param frequencies: phonon frequencies, usually indexed (qpt, mode)
   :param temperature: determines magnitude of Bose factors
   :param occupation: typically N_PLUS_ONE is used for phonon excitations

   :returns: Bose factor array corresponding to input frequencies (i.e. usually
             indexed (qpt, mode))