Behind the Diffraction Pattern: Lessons from Durham’s Intensive Crystallography School

An immersive week of structural science, skill-building, and scientific community.

May 05 2025

Earlier this month, I had the opportunity to attend the 20^th BCA/CCG Intensive Teaching School in X-Ray Structure Analysis based at Durham University. This intensive week-long course focused on the theory and practice of X-ray crystallography and attracts students and researchers from across the world who are keen to deepen their understanding of structural science.

As a PhD student in Chemistry, crystallography is essential to my research into the design of novel copper complexes whose emissive propertied offer potential for OLED application in the automotive industry. The ability to determine precise molecular structures is critical for linking chemical design to function – especially when tuning optical properties and electronic behaviour for advanced materials.

Attending this school allowed me to strengthen my theoretical knowledge, develop my practical skills in structure determination and refinement, and engage with experts who are actively shaping the field. The week was intense, fast-paced, and incredibly rewarding – providing not just technical knowledge, but also deeper insight into how molecular structure influences material properties. For my research, where small changes in geometry or interactions can affect emission behaviour, this perspective is invaluable.

The Foundations of Crystallographic Analysis

XRD, or X-ray diffraction, is at the heart of crystallographic studies. This technique allows us to ‘see’ the arrangements of atoms within a material by analysing how interactions with an ordered crystal lattice causes x-rays to scatter. This method has been fundamental to major scientific breakthroughs, from determining the structure of DNA to designing advanced materials and molecular devices. The principle is such that incident x-rays will interact with the atoms within a crystal, causing them to diffract in specific directions at certain angles, and the result of this creates a pattern containing information about those crystals’ internal structure on an atomic level. The Bragg equation is fundamental in diffraction analysis and reveals the intrinsic relationship between diffraction and crystal structure. When x-rays irradiate a crystal, the optical path difference between adjacent crystal places is nλ=2dsinθ, where:

λ = the wavelength of the x-ray

d = the interplanar spacing of the crystal lattice

θ = the angle between the incident x-ray and the corresponding crystal place

However, solving an entire crystal structure is not as straightforward as applying Bragg’s Law alone, as this only offers limited insight into the full three-dimensional arrangement of atoms. To move from raw diffraction data to an interpretable structure, we rely on Fourier transforms to reconstruct electron density maps. This process introduces a far more complex mathematical framework, often represented by equations that can appear daunting at first glance:

Understanding the principles behind these transformations is essential for converting experimental data into meaningful atomic models and forms the backbone of modern crystallographic analysis.

One key challenge in this process is the phase problem – the fact that diffraction patterns provide intensities but not phases, which are crucial for accurately reconstructing electron density maps. While most of this process is now done by software, having a conceptual understanding of the underlying mathematics – such as Fourier transforms – helps in noticing and diagnosing issues and in refining more complex structures effectively. For my own work with copper-based emissive compounds, resolving atomic positions is essential for correlating structural features with optical properties, as well as fully characterising these compounds, making this theoretical foundation supportive of my research.

Beyond the Data: People, Plays, and Perspective

After several intense days of theory-heavy lectures, structure refinement and the recurring Fourier equations, it quickly became clear that the crystallography school wasn’t just about mastering data manipulation – it was about the people, the creativity, and the learning that happens in between.

The week was packed with daily tutorials and workshops, along with opportunities to ask questions, both to a structured panel with experienced academics and informally over coffee with fellow PhD students. These conversations were some of the most valuable moments of the week, offering insight both into how others use crystallographic techniques, but also into the real career paths people have followed, their research challenges, and the many ways people have grown in science. It might seem like you aren’t developing while you’re in the middle of the mess, but when you get to the end, you’ll be able to see how much you grew.

Midweek brought a very welcome break to explore Durham in the sunshine, wandering the cobbled streets, visiting the cathedral and getting to know other attendees beyond space groups and symmetry elements. The warm weather, friendly atmosphere and shared sense of challenge fostered a real sense of community. The tutorials were an amazing collaborative space, allowing us to help each other through intense mathematics, and bond over common mistakes and challenges.

But nothing captured the spirit of the school quite like the series of crystallography-themed plays performed by each group at the end of the week. One standout featured a scouse Dora the Explorer, discovering a mystery crystal, solving its structure with help from a minion, the incredible hulk and Super flip, while fending off sabotage from the evil fox, Swiper (who had trapped the crystal’s structure in inverse space).

I narrated our horror in gothic clothing, nodding to the melodrama of twinning and a collection gone wrong. Acting out concepts like crystal refinement and space groups with cardboard props and questionable accents really helps you remember them and laugh about them too.

What I’m Taking with Me

Reflecting on the week, one of the most important lessons wasn’t from a slide or a textbook: it was the reminder that learning happens best when you go at your own pace, ask for help when you need it, and treat yourself with compassion. Crystallography is complex, and no one solves a structure alone. Whether through peer support during tough tutorial questions or sharing a laugh during chaotic group performances, the message was the same: fun helps you learn, and community helps you through the hard bits.

As a practical takeaway, the Cambridge Crystallographic Data Centre (CCDC) is a phenomenal resource, one I’ll be making much more use of in my future work. I left Durham with new skills, a deeper appreciation for structure refinement, and a lot more confidence in tackling the crystallographic aspects of my research.

Acknowledgements

I’d like to thank the sponsors of the Durham Crystallography School, listed below, along with the programme committee, for making such a rich, inclusive and engaging course possible. I am especially grateful to have received a bursary, which enables me to attend and benefit from this invaluable experience. The support the tutors and lecturers gave during tutorials was instrumental in helping us apply complex ideas to questions, and their enthusiasm around the topic was inspirational.

Additionally, I’m grateful to have been able to attend the Olex2 workshop, led by two of the software’s original developers. Their expert guidance in structure solution and refinement, paired with thoughtful walkthroughs and real-time troubleshooting, was an incredibly valuable learning opportunity. Getting hands-on experience with this tool I’ll use readily was a real highlight.