Skip to main content

Brian H. Toby

APS Chief Computational Scientist, Senior Physicist, Group Leader

Powder diffraction crystallography and computational x-ray science


Brian Toby is a synchrotron and neutron powder diffraction crystallographer, with ~140 refereed papers and >11,000 citations. He oversaw construction of the 11-BM diffractometer and designed and implemented its world-leading automation system. He served as Chair of the US National Committee for Crystallography, and is active in the American Crystallographic Association, the Denver X-ray Conference and the International Centre for Diffraction Data. He developed the pdCIF standard for the International Union of Crystallography. He is an editor of the journal Powder Diffraction and served on the editorial board of The Journal of Physical and Chemical Reference Data. Brian H. Toby’s professional experience has been in targeted research in a number of employment environments, including chemical industry, academia and in the government sector both in a synchrotron and a research reactor facility.

His research interests are in understanding how the arrangements of atoms in solids determine how the material functions, chemically or physically, and for the development and teaching of techniques for those studies. To do this, he works on software and instrument development as well as conducts measurements and analyzes the results. Brian has developed several novel software concepts: the first fitting program for PDFs for study of local order in crystalline materials and the first multi-field boolean search (a.k.a. PDF-4) application for powder diffraction databases. His best known programs include GSAS-II, CMPR, CIFTOOLS (pdCIFplot) and EXPGUI.


See ResearchID or ORCHID web sites


  • Physical Chemistry, Ph.D., Caltech 1986
  • Chemistry, B.A. with Honors and Highest Distinction, Rutgers College, 1980

Awards, Honors and Memberships

  • Co-recipient (with Robert Von Dreele) of the 6th American Crystallographic Association Ken Trueblood Award for exceptional achievement in computational or chemical crystallography.” (2019)
  • 16th recipient of the Charles S. Barrett Award from the Denver X-ray Conference for outstanding contributions to the field of powder diffraction” (2015)
  • Elected Chair (2012-2014) and Vice Chair (2009-2011), U.S. National Committee on Crystallography of the National Academy of Science
  • Bronze Medal for Superior Federal Service, U.S. Department of Commerce (2005)
  • Fellow, American Crystallographic Association (2017) and International Centre for Diffraction Data (2004)
  • Phi Beta Kappa (1980) and American Institute of Chemists Undergraduate Award (1980)