Overview of Atomic and X-ray Data

The data provided in XrayDB includes Atomic data and characteristic energies and cross sections for the interaction of X-rays with elements. A few definitions and conventions necessary for using this data are discussed here.

Elements

Most of the data resources are accessed by an elements Atomic Symbol. For the Python module, most methods will take element as the first argument, and this can either be the integer atomic number or the string for the atomic symbol.

Elemental densities are given in gr/cm^3, and molar masses are given in AMU.

X-ray Edges

Several resources (database tables, python methods) take either an edge or a level argument to signify a core electronic level. These must be one of the levels listed in the Table of X-ray edge names.

Table of X-ray Edges and Core electronic levels. The Names are the IUPAC symbols for the core electronic levels.

Name	electronic level	Name	electronic level
K	\(1s\)	N5	\(4d_{5/2}\)
L3	\(2p_{3/2}\)	N4	\(4d_{3/2}\)
L2	\(2p_{1/2}\)	N3	\(4p_{3/2}\)
L1	\(2s\)	N2	\(4p_{1/2}\)
M5	\(3d_{5/2}\)	N1	\(4s\)
M4	\(3d_{3/2}\)	O3	\(5p_{3/2}\)
M3	\(3p_{3/2}\)	O2	\(5p_{1/2}\)
M2	\(3p_{1/2}\)	O1	\(5s\)
M1	\(3s\)	P3	\(6p_{3/2}\)
N7	\(4f_{7/2}\)	P2	\(6p_{1/2}\)
N6	\(4f_{5/2}\)	P1	\(6s\)

X-ray Lines

Many resources (database tables or methods) take emission line arguments. These follow the latinized version of the Siegbahn notation as indicated in the Table of X-ray emission line names.

Table of X-ray emission line names and the corresponding Siegbahn and IUPAC notations

Name	IUPAC	Siegbahn	Name	IUPAC	Siegbahn
Ka1	K-L3	\(K\alpha_1\)	Lb4	L1-M2	\(L\beta_4\)
Ka2	K-L2	\(K\alpha_2\)	Lb5	L3-O4,5	\(L\beta_5\)
Ka3	K-L1	\(K\alpha_3\)	Lb6	L3-N1	\(L\beta_6\)
Kb1	K-M3	\(K\beta_1\)	Lg1	L2-N4	\(L\gamma_1\)
Kb2	K-N2,3	\(K\beta_2\)	Lg2	L1-N2	\(L\gamma_2\)
Kb3	K-M2	\(K\beta_3\)	Lg3	L1-N3	\(L\gamma_3\)
Kb4	K-N4,5	\(K\beta_2\)	Lg6	L2-O4	\(L\gamma_6\)
Kb5	K-M4,5	\(K\beta_3\)	Ll	L3-M1	\(Ll\)
La1	L3-M5	\(L\alpha_1\)	Ln	L2-M1	\(L\nu\)
La2	L3-M4	\(L\alpha_1\)	Ma	M5-N6,7	\(M\alpha\)
Lb1	L2-M4	\(L\beta_1\)	Mb	M4-N6	\(M\beta\)
Lb2,15	L3-N4,5	\(L\beta_2,L\beta_{15}\)	Mg	M3-N5	\(M\gamma\)
Lb3	L1-M3	\(L\beta_3\)	Mz	M4,5-N6,7	\(M\zeta\)

Energies

Unless otherwise stated, all energies are in units of eV.

Cross Sections

The photoabsorption and scattering cross sections from Elam, Ravel and Sieber [2] and Chantler [1] are in cm^2/gr.

The data from Elam, Ravel and Sieber [2] is held as logarithms of energy, cross section, and logarithm of the 2nd derivative of cross section that allows for cubic spline interpolation in log-log space.