update docs for atomic scattering factor (#203)

lmmentel · Nov 5, 2024 · edee533 · edee533
1 parent b98534a
commit edee533
Show file tree

Hide file tree

Showing 8 changed files with 50 additions and 115 deletions.
diff --git a/docs/source/api/mendeleev.cli.rst b/docs/source/api/mendeleev.cli.rst
@@ -4,26 +4,9 @@
 .. automodule:: mendeleev.cli
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
 
       clielement
-
-
-
-
-
-
-
-
-
-
-
-
-
+
diff --git a/docs/source/api/mendeleev.db.rst b/docs/source/api/mendeleev.db.rst
@@ -4,28 +4,11 @@
 .. automodule:: mendeleev.db
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
 
       get_engine
       get_package_dbpath
       get_session
-
-
-
-
-
-
-
-
-
-
-
-
-
+
diff --git a/docs/source/api/mendeleev.econf.rst b/docs/source/api/mendeleev.econf.rst
@@ -4,11 +4,6 @@
 .. automodule:: mendeleev.econf
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
@@ -20,21 +15,9 @@
       subshell_capacity
       subshell_degeneracy
 
-
-
-
-
    .. rubric:: Classes
 
    .. autosummary::
 
       ElectronicConfiguration
-
-
-
-
-
-
-
-
-
+
diff --git a/docs/source/api/mendeleev.electronegativity.rst b/docs/source/api/mendeleev.electronegativity.rst
@@ -4,11 +4,6 @@
 .. automodule:: mendeleev.electronegativity
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
@@ -22,16 +17,4 @@
       mulliken
       nagle
       sanderson
-
-
-
-
-
-
-
-
-
-
-
-
-
+
diff --git a/docs/source/api/mendeleev.fetch.rst b/docs/source/api/mendeleev.fetch.rst
@@ -4,18 +4,16 @@
 .. automodule:: mendeleev.fetch
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
 
+      add_plot_columns
       fetch_electronegativities
       fetch_ionic_radii
       fetch_ionization_energies
       fetch_neutral_data
       fetch_table
-
+      get_app_data
+      get_zeff
+
diff --git a/docs/source/api/mendeleev.mendeleev.rst b/docs/source/api/mendeleev.mendeleev.rst
@@ -4,30 +4,14 @@
 .. automodule:: mendeleev.mendeleev
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
 
       deltaN
       element
       get_all_elements
+      get_attribute_for_all_elements
       ids_to_attr
       isotope
-
-
-
-
-
-
-
-
-
-
-
-
-
+
diff --git a/docs/source/api/mendeleev.utils.rst b/docs/source/api/mendeleev.utils.rst
@@ -4,11 +4,6 @@
 .. automodule:: mendeleev.utils
 
 
-
-
-
-
-
    .. rubric:: Functions
 
    .. autosummary::
@@ -17,16 +12,4 @@
       coeffs
       n_effective
       render_rst_table
-
-
-
-
-
-
-
-
-
-
-
-
-
+
diff --git a/mendeleev/models.py b/mendeleev/models.py
@@ -1232,7 +1232,45 @@ class ScatteringFactor(Base):
         atomic_number (int): Atomic number
         energy (float): Energy in eV
         f1 (float): Scattering factor f1
-        f1 (float): Scattering factor f2
+        f2 (float): Scattering factor f2
+
+    :math:`f_1` and :math:`f_2` are the atomic (forward) scattering factors.
+    There are 500+ points on a uniform logarithmic mesh with points
+    added 0.1 eV above and below "sharp" absorption edges.
+    (Note: below 29 eV :math:`f_1` is set equal to -9999.)
+    The tabulated values of :math:`f_1` contain a relativistic, energy independent,
+    correction given by, :math:`Z^{*} = Z - (Z/82.5)^{2.37}`.
+
+    The atomic photoabsorption cross section, :math:`\mu_a`, may be readily obtained
+    from the values of :math:`f_2` using the relation,
+
+    .. math::
+
+        \mu_a = 2 \cdot r_0 \cdot \lambda \cdot f_2
+
+    where :math:`r_0` is the classical electron radius, and :math:`\lambda` is the wavelength.
+
+    The index of refraction for a material with N atoms per unit volume
+    is calculated by,
+
+    .. math::
+
+        n = 1 - N \cdot r_0 \cdot \lambda^2 \cdot (f_1 + i f_2)/(2\cdot\pi).
+
+    These (semi-empirical) atomic scattering factors are based upon
+    photoabsorption measurements of elements in their elemental state.
+    The basic assumption is that condensed matter may be modeled as a
+    collection of non-interacting atoms. This assumption is in general
+    a good one for energies sufficiently far from absorption thresholds.
+    In the threshold regions, the specific chemical state is important
+    and direct experimental measurements must be made.
+
+    These tables are based on a compilation of the available experimental
+    measurements and theoretical calculations. For many elements there is
+    little or no published data and in such cases it was necessary to
+    rely on theoretical calculations and interpolations across Z.
+    In order to improve the accuracy in the future considerably more
+    experimental measurements are needed.
     """
 
     __tablename__ = "scattering_factors"