Mention source of elements database in docstring

doc/reference/material.rst

@@ -18,7 +18,9 @@
 .. autoattribute:: exspy.material.elements
    :annotation:
 
-Database of element properties. The following properties are included:
+Database of element properties.
+
+The following properties are included:
 
 .. code::
 
@@ -32,32 +34,50 @@ Database of element properties. The following properties are included:
     └── Physical_properties
         └── density_gcm3
 
-Examples:
+The X-ray lines energies are taken from Chantler et al. [1]_.
 
-.. code::
+The line weight, more precisely the approximate line weight for K, L, M
+shells are taken from Electron Probe Quantification (EPQ) library [2]_.
+
+The field ``threshold`` and ``edge`` are taken from Gatan EELS atlas
+https://eels.info/atlas, as retrieved in June 2020.
+
+Examples
+
+>>> exspy.material.elements.Fe.General_properties
+├── Z = 26
+├── atomic_weight = 55.845
+└── name = iron
+>>> exspy.material.elements.Fe.Physical_properties
+└── density (g/cm^3) = 7.874
+>>> exspy.material.elements.Fe.Atomic_properties.Xray_lines
+├── Ka
+│   ├── energy (keV) = 6.404
+│   └── weight = 1.0
+├── Kb
+│   ├── energy (keV) = 7.0568
+│   └── weight = 0.1272
+├── La
+│   ├── energy (keV) = 0.705
+│   └── weight = 1.0
+├── Lb3
+│   ├── energy (keV) = 0.792
+│   └── weight = 0.02448
+├── Ll
+│   ├── energy (keV) = 0.615
+│   └── weight = 0.3086
+└── Ln
+    ├── energy (keV) = 0.62799
+    └── weight = 0.12525
+
+
+References
+
+.. [1] Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R.,
+   Kotochigova, S.A., and Zucker, D.S. (2005), X-Ray Form Factor,
+   Attenuation and Scattering Tables (version 2.1).
+   https://dx.doi.org/10.18434/T4HS32
 
-    >>> exspy.material.elements.Fe.General_properties
-    ├── Z = 26
-    ├── atomic_weight = 55.845
-    └── name = iron
-    >>> exspy.material.elements.Fe.Physical_properties
-    └── density (g/cm^3) = 7.874
-    >>> exspy.material.elements.Fe.Atomic_properties.Xray_lines
-    ├── Ka
-    │   ├── energy (keV) = 6.404
-    │   └── weight = 1.0
-    ├── Kb
-    │   ├── energy (keV) = 7.0568
-    │   └── weight = 0.1272
-    ├── La
-    │   ├── energy (keV) = 0.705
-    │   └── weight = 1.0
-    ├── Lb3
-    │   ├── energy (keV) = 0.792
-    │   └── weight = 0.02448
-    ├── Ll
-    │   ├── energy (keV) = 0.615
-    │   └── weight = 0.3086
-    └── Ln
-        ├── energy (keV) = 0.62799
-        └── weight = 0.12525
+.. [2] Ritchie, N. EPQ is the Electron Probe Quantification library
+   - the basis for DTSA-II.
+   https://github.com/usnistgov/EPQ

exspy/_misc/elements.py

@@ -4996,6 +4996,14 @@
     └── Physical_properties
         └── density_gcm3
 
+The X-ray lines energies are taken from Chantler et al. [1]_.
+
+The line weight, more precisely the approximate line weight for K, L, M
+shells are taken from Electron Probe Quantification (EPQ) library [2]_.
+
+The field ``threshold`` and ``edge`` are taken from Gatan EELS atlas
+https://eels.info/atlas, as retrieved in June 2020.
+
 Examples
 --------
 >>> exspy.material.elements.Fe.General_properties
@@ -5023,6 +5031,18 @@
 └── Ln
     ├── energy (keV) = 0.62799
     └── weight = 0.12525
+
+
+References
+----------
+.. [1] Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R.,
+   Kotochigova, S.A., and Zucker, D.S. (2005), X-Ray Form Factor,
+   Attenuation and Scattering Tables (version 2.1).
+   https://dx.doi.org/10.18434/T4HS32
+
+.. [2] Ritchie, N. EPQ is the Electron Probe Quantification library
+   - the basis for DTSA-II.
+   https://github.com/usnistgov/EPQ
 """
 
 # read dictionary of atomic numbers from eXSpy, and add the elements that

exspy/_misc/material.py

@@ -314,7 +314,7 @@ def mass_absorption_coefficient(element, energies):
     Mass absorption coefficient (mu/rho) of a X-ray absorbed in a pure
     material.
 
-    The mass absorption is retrieved from the database of Chantler2005
+    The mass absorption is retrieved from the database of Chantler et al. [*]_.
 
     Parameters
     ----------
@@ -339,12 +339,11 @@ def mass_absorption_coefficient(element, energies):
     --------
     exspy.material.mass_absorption_mixture
 
-    Note
-    ----
-    See https://dx.doi.org/10.18434/T4HS32
-    Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova,
-    S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and
-    Scattering Tables (version 2.1).
+    References
+    ----------
+    .. [*] Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova,
+       S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and
+       Scattering Tables (version 2.1). https://dx.doi.org/10.18434/T4HS32
     """
     energies_db = np.array(ffast_mac[element].energies_keV)
     macs = np.array(ffast_mac[element].mass_absorption_coefficient_cm2g)
@@ -372,7 +371,7 @@ def _mass_absorption_mixture(weight_percent, elements, energies):
     mixture of elements.
 
     The mass absorption coefficient is calculated as a weighted mean of the
-    weight percent and is retrieved from the database of Chantler2005.
+    weight percent and is retrieved from the database of Chantler et al. [*]_.
 
     Parameters
     ----------
@@ -400,12 +399,11 @@ def _mass_absorption_mixture(weight_percent, elements, energies):
     --------
     exspy.material.mass_absorption
 
-    Note
-    ----
-    See https://dx.doi.org/10.18434/T4HS32
-    Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova,
-    S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and
-    Scattering Tables (version 2.1).
+    References
+    ----------
+    .. [*] Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova,
+       S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and
+       Scattering Tables (version 2.1). https://dx.doi.org/10.18434/T4HS32
     """
     if len(elements) != len(weight_percent):
         raise ValueError("Elements and weight_fraction should have the same length")
@@ -430,7 +428,7 @@ def mass_absorption_mixture(weight_percent, elements="auto", energies="auto"):
     mixture of elements.
 
     The mass absorption coefficient is calculated as a weighted mean of the
-    weight percent and is retrieved from the database of Chantler2005.
+    weight percent and is retrieved from the database of Chantler et al. [*]_.
 
     Parameters
     ----------
@@ -461,13 +459,11 @@ def mass_absorption_mixture(weight_percent, elements="auto", energies="auto"):
     --------
     exspy.material.mass_absorption_coefficient
 
-    Note
-    ----
-    See https://dx.doi.org/10.18434/T4HS32
-    Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova,
-    S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and
-    Scattering Tables (version 2.1).
-
+    References
+    ----------
+    .. [*] Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova,
+       S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and
+       Scattering Tables (version 2.1). https://dx.doi.org/10.18434/T4HS32
     """
     from hyperspy.signals import BaseSignal
 

upcoming_changes/87.enhancements.rst

@@ -0,0 +1 @@
+Mention source of :attr:`~exspy.material.elements` database in docstring