forte2.orbitals.iao
===================

.. py:module:: forte2.orbitals.iao




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

.. py:class:: IAO(system: forte2.system.System, C_occ: numpy.ndarray, j_adapt=False)

   
   Class to represent the intrinsic atomic orbital (IAO).


   :Parameters:

       **system** : System
           The system for which the IAO is to be calculated.

       **C_occ** : NDArray
           The occupied molecular orbital coefficients.

   :Attributes:

       **C_iao** : NDArray
           The orthonormalized IAO coefficients, shape (nbf, nminao).










   .. rubric:: Notes

   JCTC 2013, 9, 4834-4843



   ..
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   .. py:attribute:: system


   .. py:attribute:: C_occ


   .. py:attribute:: j_adapt
      :value: False



   .. py:attribute:: C_iao


   .. py:attribute:: nocc


   .. py:method:: make_sf_1rdm(sf_1rdm_ao)

      
      Generate the spin-free 1-particle density matrix in the IAO basis, given by

      .. math::
          \gamma_{\rho\sigma} = \langle\rho|\hat{\gamma}|\sigma\rangle,

      where :math:`\hat{\gamma}=2\sum_{i \in \text{occ}} |i\rangle\langle i|` is the
      closed-shell RHF 1e density matrix (see eq 3 in the JCTC paper).

      :Parameters:

          **sf_1rdm_ao** : NDArray
              The spin-free 1-particle density matrix in the large AO basis.



      :Returns:

          NDArray
              The spin-free 1-particle density matrix in the IAO basis.











      ..
          !! processed by numpydoc !!


.. py:class:: IBO(system: forte2.system.System, C_occ: numpy.ndarray, maxiter=10, g_tol=1e-08)

   Bases: :py:obj:`IAO`


   
   Class to represent the intrinsic bond orbital basis.


   :Parameters:

       **system** : System
           The system for which the IBO is to be calculated.

       **C_occ** : NDArray
           The occupied molecular orbital coefficients.

       **maxiter** : int, optional, default=10
           The maximum number of iterations for the IBO optimization.

       **g_tol** : float, optional, default=1e-8
           The RMS gradient convergence criterion for the IBO optimization.











   .. rubric:: Notes

   There are typos in the original paper, specifically for the Aij and Bij elements.
   See the corrected paper at
   http://www.iboview.org/bin/iao_preprint.pdf
   also see the reference implementation at
   https://sites.psu.edu/knizia/software/



   ..
       !! processed by numpydoc !!

   .. py:attribute:: maxiter
      :value: 10



   .. py:attribute:: g_tol
      :value: 1e-08



   .. py:attribute:: C_ibo