Abstract by David Anderson

Personal Infomation

Presenter's Name

David Anderson

Degree Level



Branton Campbell

Abstract Infomation


Physics and Astronomy

Faculty Advisor

Branton Campbell


Applying Symmetry Modes to Rietveld Refinement


Rietveld analysis is a technique for determining the atomic structure of a crystalline material from x-ray or neutron powder diffraction data, and is useful for quantifying the symmetry-breaking distortions that arise in crystal-crystal phase transitions.  Because the symmetry-mode parameter set (basis functions of irreducible representations or "irreps") is very often the most natural and compact description of a phase transition, the ability to directly refine symmetry-mode amplitudes rather than traditional atomistic parameters has proven to be highly advantageous.  I am working to enable direct symmetry-mode refinements in widely-used Rietveld-analysis packages.