# 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.

## Physical Units¶

Elemental densities are given in gr/cm^3, and molar masses are given in AMU. Unless otherwise stated, all energies are in units of eV.

## X-ray Edges¶

Several resources (database tables, python methods) take either an `edge`

or a `level`

argument to signify a core electronic level. These are
strings and 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 are all strings and 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

\(M\zeta\)

## Cross Sections¶

The photo-absorption and scattering cross sections from [Elam, Ravel, and Sieber (2002)] and [Chantler (2000)] are in cm^2/gr.

The data from [Elam, Ravel, and Sieber (2002)] 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.