forte2.orbitals.aset
====================

.. py:module:: forte2.orbitals.aset




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

.. py:class:: ASET

   Bases: :py:obj:`forte2.base_classes.mixins.MOsMixin`, :py:obj:`forte2.base_classes.mixins.SystemMixin`, :py:obj:`forte2.base_classes.mixins.MOSpaceMixin`


   
   Active Space Embedding Theory (ASET) method for paritioning and projecting molecules.


   :Parameters:

       **fragment** : list[str]
           List of atomic symbols defining the fragment.

       **frozen_core_orbitals** : int | list[int], optional, default=None
           Number or list of frozen core orbital indices.

       **frozen_virtual_orbitals** : int | list[int], optional, default=None
           Number or list of frozen virtual orbital indices.

       **cutoff_method** : str, optional, default="threshold"
           Method for choosing the embedding cutoff. Options include "threshold", "num_of_orbitals".

       **cutoff** : float, optional, default = 0.5
           Projector eigenvalue for simple threshold methods.

       **num_A_occ** : int, optional, default=0
           Number of occupied orbitals fixed to this value in fragment A when cutoff method is "num_of_orbitals".

       **num_A_vir** : int, optional, default=0
           Number of virtual orbitals fixed to this value in fragment A when cutoff method is "num_of_orbitals".

       **semicanonicalize_active** : bool, optional, default=True
           Whether to semicanonicalize the active space orbitals.

       **semicanonicalize_frozen** : bool, optional, default=True
           Whether to semicanonicalize the frozen orbitals.











   .. rubric:: Notes

   The allowed subspace specification is a list of strings, non-exhaustive examples::

   - ["C"]              # all carbon atoms
   - ["C","N"]          # all carbon and nitrogen atoms
   - ["C1"]             # carbon atom #1
   - ["C1-7"]           # carbon atoms #1 through #7
   - ["C1-3","N2"]      # carbon atoms #1, #2, #3 and nitrogen atom #2

   See J. Chem. Phys. 2020, 152 (9), 094107 <https://doi.org/10.1063/1.5142481>_ for details on the ASET(mf) method.



   ..
       !! processed by numpydoc !!

   .. py:attribute:: fragment
      :type:  list


   .. py:attribute:: frozen_core_orbitals
      :type:  int | list[int]
      :value: None



   .. py:attribute:: frozen_virtual_orbitals
      :type:  int | list[int]
      :value: None



   .. py:attribute:: cutoff_method
      :type:  str
      :value: 'threshold'



   .. py:attribute:: cutoff
      :type:  float
      :value: 0.5



   .. py:attribute:: num_A_occ
      :type:  int
      :value: 0



   .. py:attribute:: num_A_vir
      :type:  int
      :value: 0



   .. py:attribute:: semicanonicalize_active
      :type:  bool
      :value: True



   .. py:attribute:: semicanonicalize_frozen
      :type:  bool
      :value: True



   .. py:attribute:: executed
      :type:  bool
      :value: False



   .. py:method:: run()