Data Sources

The data used in this package comes from the following data providers.

  • The U.S National Institute of Standards and Technology (NIST)
  • The Center for X-ray Optics and Advanced Light Source (CXRO) at the Lawrence Berkeley National Laboratory

We would like to extend our thanks to these groups for making their data public.

The CXRO publish primarily makes their data available through the X-ray Data Booklet.

The following list the data files contained in the data directory along with their source and other relevant information to properly interpret the data therein.

The elements and compounds_mixtures folders contains mass attenuation coefficients from the NIST. More specifically, elements are from here while compounds and mixtures are from here.


Source: Provides translation between atomic number, element names, and element symbols. Energy ranges from 1 keV to 20 MeV.

  • z: Atomic number
  • name: Element name
  • zovera: Ratio of atomic number-to-mass (Z/A)
  • i: mean excitation energy I in eV
  • density: density in g/cm^3


Source: Provides a list of all compounds and mixtures supported density is in units of g/cm^3 Energy ranges from 1 keV to 20 MeV.


Source: CXRO X-ray data Booklet Table 1-3

  • energy: Energy of emission line in eV
  • transition: Name of the transition in Siegbahn notation
  • intensity: Relative intensity of the line


Source: CXRO X-ray data Booklet Table 1-3 energy in eV


Source CXRO X-ray data Booklet Table 1-1 energies in eV