The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

GSAS-II Users' Meeting

Monthly GSAS-II Users' Meeting
Second Monday of the Month
1:00 p.m. - 2:00 p.m. 401/B4100

GSAS-II is an APS-developed software package for x-ray and neutron diffraction, supporting data analysis techniques that include single-crystal crystallography, powder diffraction crystallography (Rietveld analysis), stress and texture measurements, small-angle scattering, area detector calibration and integration, and reflectometry. It replaces the aging GSAS/EXPGUI packages, which are currently cited ~500 times/year, but GSAS-II offers many more capabilities, and sees a citation rate doubling each year. This monthly topical meeting is intended for ANL-based scientists who use GSAS-II at their beamlines or in their research.

Next meeting:  October 12, 2020, 1-2 pm, BlueJeans (

Topic:  TBD

Future meetings:

  • To Be Determined

Past Meetings:

  • December 9, 2019
  • August 12, 2019: BYOB: Bring Your Own Bug [Notes]
  • April 8, 2019. Progress/Requests [Notes]
  • March 11, 2019. Progress/Requests [Notes]
  • February 11, 2019. Progress/Requests [Notes]
  • April 9, 2018: Topic: Scripting integration. [Notes/requests]
  • March 12, 2018: News: Progress in treating magnetic symmetry (RBVD); New options for publication-quality plots (BHT) [no slides]
  • January 8, 2018: PDF computation, validation & modeling needs. Intro from Chris Benmore [Slides]
  • December 11, 2017: Improvements in image integration/auto integration GUI; Handling of 1-ID metadata. [Slides & completed request]
  • September 11, 2017: Discussions on PDF computation and modeling [What's New Slides; discussion/development requests]
  • August 14, 2017: metadata handling and image import issues [development requests]
  • July 10, 2017: Overview of recent changes (new GUI, speedup work). Main focus: new changes to the Sequential/Parametric fitting code and input on limitations & improvements. (Discussion notes added to slides.) [What's New Slides]
  • June 12, 2017: Reflectometry. This meeting was devoted to the x-ray and neutron reflectometry fitting capability that is being developed in GSAS-II. Bob Von Dreele outlined what has been developed and any planned further development work with discussion on possible limitations or improvements. Users are still encouraged to provide data, fitted parameters, and results from previous projects on USB sticks or shared via Box.
  • May 15, 2017: Brief overview of GSAS-II capabilities; development recently completed, in progress, planned and desired. (Discussion notes added to slides.) [​Slides, ​audio recording]