ATSAS software

ATSAS is the world most comprehensive and powerful program suite for small angle scattering data analysis from biological macromolecules in solution. The suite is freely available for academic users upon registration. BIOSAXS offers various types of licenses for commercial customers.
With ATSAS you can:

  • evaluate the overall geometrical parameters of your sample (radius of gyration (Rg), molecular weight etc.);
  • reconstruct the shape of proteins and other macromolecules in solution ab initio (i.e. based only on SAXS data);
  • build models using data from complementary methods (X-ray crystallography, NMR, bioinformatics etc.);
  • analyse oligomeric mixtures and flexible systems (including intrinsically disordered proteins).

ATSAS includes a number of programs with a graphical user interface (GUI) for interactive data analysis. On the screenshot above, clockwise: PRIMUS for processing of experimental data; GNOM is an indirect Fourier transform program that provides the pair distance distribution function p(r); interactive Guinier analysis provides Rg and I(0) estimates; below the PRIMUS window is the PyMOL plugin SASpy.

ATSAS includes a number of command-line tools which are useful for automation of processing of large amounts of experimental data.

ATSAS is installed as a single package where all programs, libraries and manuals are included. 64 bit installation packages are available for:

  • Windows 8 and 10;
  • macOS 10.12 Sierra, 10.13 High Sierra and 10.14 Mojave;
  • Red Hat/CentOS 7 and 8;
  • Ubuntu 16, 18, 20;
  • Debian 9 and 10.

If your operating system is not in this list, customized installations may be possible, please contact us at

Commercial ATSAS licenses

We offer single- and multi-user, multi-site and multi-OS ATSAS licenses, both perpetual with one year of free upgrades and annual renewal plans including upgrades beyond the first year. Please contact us at for a price offer.