# X-ray DB: X-ray Reference Data in SQLite¶

XrayDB provides atomic data, characteristic X-ray energies, and X-ray cross sections for the elements in an SQLite3 database, xraydb.sqlite. This file can be used directly with SQLite using standard SQL, or from the many programming language that support SQLite. Some of the components of the database hold arrays of numbers which are stored in the database as JSON-encoded strings, and will need to be unpacked to be used. A Python module providing such an interface is provided here.

The project began with the data from the compilation of basic atomic properties and X-ray absorption edge energies, emission energies, and absorption cross sections from , who assembled data from a several sources. More data has been added from other sources. Energy widths of core holes for excited electronic levels from and . Elastic X-ray scattering data, $$f_0(q)$$ is taken from . Resonant scattering cross sections $$f'(E)$$ and $$f''(E)$$ and absorption cross sections from as from the FFAST webpage (but on a finer energy grid, data from ) are also included.

The values here use units that are SI and commonly used in X-ray work. Cross sections are in cm^2/gr, and energies are in eV. Energy-dependent data for cross-sections are typically most reliable between about 250 eV to about 250,000 eV. Elements from Z=1 to 92 are supported, with some data are included for elements between Z=93 and Z=98.

The current version of the XrayDB is 8.1, and the version of the Python module is 4.4.7. See Also: