Frontiers of Crystallography: A Project-Based Research-Led Learning Exercise

Abstract

A highly interactive research-led learning session for chemistry undergraduates is described, which aims to lead students to an awareness of the applications of crystallography technique through a mentored hands-on crystal structure solution and refinement session. The research-based environment is inherent throughout the 4.5 h program and is emphasized by several features in the learning experience.

Structure Analysis from Powder Diffraction Data: Rietveld Refinement in Excel

“…This is an iterative multi-step process in which the model (hopefully) improves in each cycle of refinement and is used to initiate a subsequent minimization cycle. The process is normally followed by monitoring the weighted profile R factor, Rwp, which should tend to a low value: (15) or a quantity such as goodness of fit (GoF) or , which relates Rwp to the statistically expected value Rexp:…”

“…It also leads to significant gaps developing between the theory students see in lectures and textbooks, and the way they experience crystallography in a practical setting. Several publications have previously raised the educational consequences, and there have been a number of earlier papers on how to build crystallographic education into school, undergraduate and postgraduate, curricula. − Several previous publications have described ways in which powder diffraction experiments can be introduced into undergraduate practical classes to highlight the importance of the technique itself, ,− or its use as a characterization method as part of a wider laboratory practical. − We are, however, unaware of other work that teaches structure analysis from powder diffraction data in the way described here.…”

Resolving Space-Group-Choice Dilemma in Small-Molecule Crystallography for Chemistry Students Using Case-Based Learning Modules

“…The development of technology and software related to crystallography in the past few decades revolutionized how we access structural information, design research programs, and collaborate across different fields. , Small-molecule single-crystal X-ray diffraction is becoming a routine, conventional technique to chemists of various backgrounds and research interests. − The result of such ubiquity is that crystallography, to some people, is considered “a solved problem.” Indeed, the idea of simply pushing a series of buttons, and the computer will automatically generate the corresponding molecular structure is what one would expect for a reliable and well-developed technique. Although a variety of crystallography modules have been developed and incorporated in different curriculums, in a lecture or lab setting, − formal crystallography education in the United States has declined significantly over the past decades . However, it is exactly this level of comfort toward crystallography that also has caused several corrections and retractions on high-profile publications by some researchers due to their lack of appropriate training and understanding of basic but important concepts.…”

Crystallographic education in the 21st century

“…This began more aggressive efforts on the part of the ACA and the IUCr Education Committee and Commission on Crystallographic Teaching to regularly organize microsymposia focused on incorporating, in pedagogically sound ways, crystallographic science, both methods and content, into core undergraduate science curricula. The ACA and IUCr web sites hold many materials described in these symposia, and there are a number of excellent examples of exercises and content designed to teach students about diffraction and the valuable contributions of crystallography to modern science and technology (Ortiz et al, 2013;Wilson et al, 2012;Pett, 2010;Battle et al, 2010;Faust et al, 2008Faust et al, , 2010Kantardjieff, Lind et al, 2010;Kantardjieff, 2010).…”