.. auto-generated by dev_tools.docs.nxdl from the NXDL source contributed_definitions/NXabsorption_edge.nxdl.xml -- DO NOT EDIT

.. index::
    ! NXabsorption_edge (base class)
    ! absorption_edge (base class)
    see: absorption_edge (base class); NXabsorption_edge

.. _NXabsorption_edge:

=================
NXabsorption_edge
=================

**Status**:

  *base class* (contribution), extends :ref:`NXobject`

**Description**:

  .. collapse:: An absorption edge is a sharp discontinuity in the X-ray absorption spectrum ...

      An absorption edge is a sharp discontinuity in the X-ray absorption spectrum
      of an atom that occurs when the incident photon energy reaches the threshold
      energy for exciting the atom from its neutral ground state to a core-vacancy
      state.

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXatom`

.. index:: NXatom (base class); used in base class

**Structure**:

  .. _/NXabsorption_edge/name-field:

  .. index:: name (field)

  **name**: (optional) :ref:`NX_CHAR <NX_CHAR>` 

    .. collapse:: Name of the absorption edge using `IUPAC notation`_ (e.g., ``K``, ...

        Name of the absorption edge using `IUPAC notation`_ (e.g., ``K``,
        ``L2``, ``M5``), which identifies the core-vacancy state of the
        atom.

        Correspondence between IUPAC notation and electron configuration,
        expressed as vacancy notation (superscript :math:`-1`):

        .. list-table::
           :header-rows: 1

           * - IUPAC
             - Electron configuration
           * - K
             - :math:`1s^{-1}`
           * - L1
             - :math:`2s^{-1}`
           * - L2
             - :math:`2p_{1/2}^{-1}`
           * - L3
             - :math:`2p_{3/2}^{-1}`
           * - M1
             - :math:`3s^{-1}`
           * - M2
             - :math:`3p_{1/2}^{-1}`
           * - M3
             - :math:`3p_{3/2}^{-1}`
           * - M4
             - :math:`3d_{3/2}^{-1}`
           * - M5
             - :math:`3d_{5/2}^{-1}`
           * - N1
             - :math:`4s^{-1}`
           * - N2
             - :math:`4p_{1/2}^{-1}`
           * - N3
             - :math:`4p_{3/2}^{-1}`
           * - N4
             - :math:`4d_{3/2}^{-1}`
           * - N5
             - :math:`4d_{5/2}^{-1}`
           * - N6
             - :math:`4f_{5/2}^{-1}`
           * - N7
             - :math:`4f_{7/2}^{-1}`
           * - O1
             - :math:`5s^{-1}`
           * - O2
             - :math:`5p_{1/2}^{-1}`
           * - O3
             - :math:`5p_{3/2}^{-1}`
           * - O4
             - :math:`5d_{3/2}^{-1}`
           * - O5
             - :math:`5d_{5/2}^{-1}`
           * - O6
             - :math:`5f_{5/2}^{-1}`
           * - O7
             - :math:`5f_{7/2}^{-1}`
           * - P1
             - :math:`6s^{-1}`
           * - P2
             - :math:`6p_{1/2}^{-1}`
           * - P3
             - :math:`6p_{3/2}^{-1}`
           * - P4
             - :math:`6d_{3/2}^{-1}`
           * - P5
             - :math:`6d_{5/2}^{-1}`

        Per IUPAC, subscripts may be dropped when unknown or irrelevant.
        When two spin-orbit split levels are not distinguished, they may be
        written together (e.g. ``L2,3``).

        .. _IUPAC notation: https://doi.org/10.1002/xrs.1300200308

        Any of these values:

          * ``K``

          * ``L1``

          * ``L2``

          * ``L3``

          * ``L2,3``

          * ``M1``

          * ``M2``

          * ``M3``

          * ``M2,3``

          * ``M4``

          * ``M5``

          * ``M4,5``

          * ``N1``

          * ``N2``

          * ``N3``

          * ``N2,3``

          * ``N4``

          * ``N5``

          * ``N4,5``

          * ``N6``

          * ``N7``

          * ``N6,7``

          * ``O1``

          * ``O2``

          * ``O3``

          * ``O2,3``

          * ``O4``

          * ``O5``

          * ``O4,5``

          * ``O6``

          * ``O7``

          * ``O6,7``

          * ``P1``

          * ``P2``

          * ``P3``

          * ``P2,3``

          * ``P4``

          * ``P5``

          * ``P4,5``


  .. _/NXabsorption_edge/energy-field:

  .. index:: energy (field)

  **energy**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ENERGY <NX_ENERGY>`} 

    Energy of the absorption edge.

  .. _/NXabsorption_edge/atom-group:

  **atom**: (optional) :ref:`NXatom` 

    The atom whose core electron is excited at this absorption edge.

    .. _/NXabsorption_edge/atom/name-field:

    .. index:: name (field)

    **name**: (optional) :ref:`NX_CHAR <NX_CHAR>` :ref:`⤆ </NXatom/name-field>`

      Chemical symbol of the element (e.g. ``Fe``, ``Cu``).


Hypertext Anchors
-----------------

List of hypertext anchors for all groups, fields,
attributes, and links defined in this class.


* :ref:`/NXabsorption_edge/atom-group </NXabsorption_edge/atom-group>`
* :ref:`/NXabsorption_edge/atom/name-field </NXabsorption_edge/atom/name-field>`
* :ref:`/NXabsorption_edge/energy-field </NXabsorption_edge/energy-field>`
* :ref:`/NXabsorption_edge/name-field </NXabsorption_edge/name-field>`

**NXDL Source**:
  https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/contributed_definitions/NXabsorption_edge.nxdl.xml