Researchers at the University of Tokyo have developed a new computational method to determine the structure of crystal materials efficiently. This method can do so from the patterns of powder X-rays passing through crystals roughly the same size as coffee particles.
Unlike the conventional methods, this approach does not require the “lattice constant” – a geometrical constant that measures the distance between atoms in the crystal and can be applied to existing unanalyzed data. Therefore, this computational method can accelerate the search for new materials or material phases.
Most materials have “phases,” or crystal structures, even in their solid state. Studying these crystal structures offers better insights into their properties, thereby helping formulate strategies to develop new materials.
However, traditional methods require prior crystal knowledge to determine the structure, making it harder to demarcate the existing experimental data. This also highlights the possibility of undiscovered hidden structures in existing data sets.
Additionally, conventional methods employ costly computational methods. Researchers were keen to develop methods that could directly underscore crystal structure to reduce these efforts and computational costs.
“The crystal structures of the real world are extremely diverse. They are one of nature’s deepest mysteries. We thought that, in a way, we could get a glimpse of the depth of nature’s mysteries by developing our own method for determining unknown crystal structures,” says Yuuki Kubo.
Researchers developed an efficient model based on molecular dynamics that simulates atomic motion by calculating the forces between atoms. To further enhance the dexterity, the team integrated the experimental X-ray diffraction data.
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After conceiving a new model, the lead authors, Yuuki Kubo and Shiji Tsuneyuki, confirmed its proficiency by applying it to widely researched materials. The technique successfully demonstrated the crystal structures of carbon (graphite and diamond) and silicon dioxide (low-quartz, low-cristobalite, and coesite).
“We did not believe this method was promising. We were surprised when we ran the test calculations and the method performed far better than we had initially expected,” says Kubo.
Following the effectiveness, the lead authors are already hoping to use it on materials and discover new material structures.
“We plan to apply this method to powder diffraction experimental data that have remained unutilized due to unsuccessful structural determination, aiming to discover new material phases,” says the lead author.
“Furthermore, we aim to develop methods integrating experiments and simulations to determine not only crystal structures but also the structures of surfaces and interfaces.“
Journal Reference
- Yuuki Kubo, Ryuhei Sato, Yuansheng Zhao,Takahiro Ishikawa, and Shinji Tsuneyuki. 2024. Data-Assimilated Crystal Growth Simulation for Multiple Crystalline Phases. The Journal of Chemical Physics. DOI: 10.1063/5.0223390
