improve NXelectron_level

applications/NXxas_new.nxdl.xml

@@ -110,7 +110,7 @@
             <doc>Excited element</doc>
             <field name="symbol"></field>
         </group>
-        <group type="NXelectron_level" name="absorption_edge">
+        <group type="NXxray_level" name="absorption_edge">
             <doc>Excited electron level</doc>
             <field name="name"></field>
         </group>
@@ -121,7 +121,7 @@
 
                 The emission lines are described as a list of names of the form
                 *"INITIAL-FINAL"* where *INITAL* and *FINAL* are electron levels
-                as listed for :ref:`here &lt;/NXelectron_level/name-field&gt;`.
+                as listed for :ref:`here &lt;/NXxray_level/name-field&gt;`.
             </doc>
             <dimensions rank="1">
                 <dim index="1" value="nTransitions"/>

base_classes/NXxray_level.nxdl.xml

@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<?xml-stylesheet type="text/xsl" href="nxdlformat.xsl" ?>
+<!--
+# NeXus - Neutron and X-ray Common Data Format
+#
+# Copyright (C) 2008-2022 NeXus International Advisory Committee (NIAC)
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 3 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# For further information, see http://www.nexusformat.org
+-->
+<definition
+	name="NXxray_level"
+    type="group"
+    extends="NXobject"
+	category="base"
+	xmlns="http://definition.nexusformat.org/nxdl/3.1"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://definition.nexusformat.org/nxdl/3.1 ../nxdl.xsd"
+    >
+    <doc>
+      The electronic state of an atom occurring as initial or final state of a process
+      involving the absorption or emission of X-ray radiation.
+
+      The energy of an atom with one missing electron is referred to as an *X-ray level*. It is a
+      multi-electronic state which occurs as a result of the photoemission of one electron.
+    </doc>
+    <field name="name" type="NX_CHAR" optional="false">
+      <doc>
+        The *X-ray level* name as recommended by `IUPAC &lt;https://doi.org/10.1002/xrs.1300200308&gt;`_.
+
+        The corresponding :math:`nl_{j}^{-1}` notation of the electron configuration is also provided:
+
+        * *n* the principal quantum number (shell)
+        * *l* the orbital angular momentum quantum number (subshell, expressed with letters *s=0*, *p=1*, *d=2*, ...)
+        * *j = l + s* the total angular momentum (spin-orbit splitting)
+        * *s=±½* the spin angular momentum quantum number
+        * :math:`^{-1}` refers to one missing electron
+
+        The subshell energy levels are split due to the unpaired electron left behind after photoemission of
+        one electron, that may have a parallel or antiparallel alignment to the orbital momentum.
+      </doc>
+      <enumeration>
+        <item value="K"> <doc>:math:`1s^{-1}`</doc> </item>
+        <item value="L1"> <doc>:math:`2s^{-1}`</doc> </item>
+        <item value="L2"> <doc>:math:`2p_{1/2}^{-1}`</doc> </item>
+        <item value="L3"> <doc>:math:`2p_{3/2}^{-1}`</doc> </item>
+        <item value="M1"> <doc>:math:`3s^{-1}`</doc> </item>
+        <item value="M2"> <doc>:math:`3p_{1/2}^{-1}`</doc> </item>
+        <item value="M3"> <doc>:math:`3p_{3/2}^{-1}`</doc> </item>
+        <item value="M4"> <doc>:math:`3d_{3/2}^{-1}`</doc> </item>
+        <item value="M5"> <doc>:math:`3d_{5/2}^{-1}`</doc> </item>
+        <item value="N1"> <doc>:math:`4s^{-1}`</doc> </item>
+        <item value="N2"> <doc>:math:`4p_{1/2}^{-1}`</doc> </item>
+        <item value="N3"> <doc>:math:`4p_{3/2}^{-1}`</doc> </item>
+        <item value="N4"> <doc>:math:`4d_{3/2}^{-1}`</doc> </item>
+        <item value="N5"> <doc>:math:`4d_{5/2}^{-1}`</doc> </item>
+        <item value="N6"> <doc>:math:`4f_{5/2}^{-1}`</doc> </item>
+        <item value="N7"> <doc>:math:`4f_{7/2}^{-1}`</doc> </item>
+        <item value="O1"> <doc>:math:`5s^{-1}`</doc> </item>
+        <item value="O2"> <doc>:math:`5p_{1/2}^{-1}`</doc> </item>
+        <item value="O3"> <doc>:math:`5p_{3/2}^{-1}`</doc> </item>
+        <item value="O4"> <doc>:math:`5d_{3/2}^{-1}`</doc> </item>
+        <item value="O5"> <doc>:math:`5d_{5/2}^{-1}`</doc> </item>
+        <item value="O6"> <doc>:math:`5f_{5/2}^{-1}`</doc> </item>
+        <item value="O7"> <doc>:math:`5f_{7/2}^{-1}`</doc> </item>
+        <item value="O8"> <doc>:math:`5g_{7/2}^{-1}`</doc> </item>
+        <item value="O9"> <doc>:math:`5g_{9/2}^{-1}`</doc> </item>
+        <item value="P1"> <doc>:math:`6s^{-1}`</doc> </item>
+        <item value="P2"> <doc>:math:`6p_{1/2}^{-1}`</doc> </item>
+        <item value="P3"> <doc>:math:`6p_{3/2}^{-1}`</doc> </item>
+        <item value="P4"> <doc>:math:`6d_{3/2}^{-1}`</doc> </item>
+        <item value="P5"> <doc>:math:`6d_{5/2}^{-1}`</doc> </item>
+        <item value="P6"> <doc>:math:`6f_{5/2}^{-1}`</doc> </item>
+        <item value="P7"> <doc>:math:`6f_{7/2}^{-1}`</doc> </item>
+      </enumeration>
+    </field>
+</definition>