Research CMM great leap forwards in uncovering atomic geometry next-gen materials

(11-02-2021) CMM’s research at Ghent University uses quantum mechanical calculations in the design of next-generation materials, which is an enormous breakthrough in the field of atomic structure choice for modular materials.

As next-generation materials become increasingly complex to meet the strict demands of modern-day applications in chemical industry, energy conversion and more, so does their atomic-level structure. This complexity makes it very challenging to exactly identify the structure of experimental samples, especially since scientists rarely have an overview of all structural possibilities. New research from the Center for Molecular Modeling (CMM) at Ghent University levels the playing field by constructing all possible models and ranking them using quantum mechanical calculations, until only one model remains. This process is an enormous leap forward from the process of making an educated guess that material designers have been using up till now to determine the correct atomic structure of modular materials.

Great number of possibilities

In modular materials, rigid building blocks are assembled into periodic patterns on the nanoscale. This makes these materials incredibly versatile and able to deal with various technological challenges since specific building blocks can be selected to meet the needs of specific applications, such as energy storage, shock absorption, greenhouse gas capture, or catalysis. However, the sheer number of possible ways in which the building blocks can be combined often makes the characterization of their structure an arduous process. Fortunately, researchers at the Center for Molecular Modeling (CMM) at Ghent University have proposed a protocol to meet this challenge head-on, which has now been published in Angewandte Chemie.

All models

Traditionally, to come to the correct atomic-level structure for modular materials, scientists make an educated guess based on material behavior and compatibility to other possible building blocks. This guesswork is often ambiguous and encourages a strong bias for earlier models. In contrast, the new approach completely reverses this workflow.

The new methodology starts by combining the different building blocks in a computer to form all conceivable combinations. This eliminates the ambiguity of the initial guess, leading to an easy-to-use, systematic and reliable workflow. Subsequently, all models are subjected to quantum mechanical calculations to accurately determine the atoms’ behavior on the nano scale. This enables comparison between the different possible models with the experiment and allows a ranking to be made.

Future prospects

One of the most challenging aspects of this approach is to mimic the experiment as closely as possible within a computer simulation. At room temperature, for instance, atoms inside the experimental sample tend to be much more dynamic than at colder temperatures, moving around inside the material over time. These dynamics need to be accounted for, also in the quantum mechanical calculations used to rank the different hypothetical models. In the newly published procedure, these dynamics are correctly accounted for, resulting in unprecedented correspondence between experimental and theoretical XRD patterns. In turn, this offers a reliable basis upon which to determine the correct atomic-level structure of these materials.

"These results show great potential in terms of determining the atomic structure of complex materials and, in doing so, understanding what makes their design so revolutionary. By using this knowledge, new design principles can be established to build next-generation materials with even better performance, ushering in a new era in material design." (dr. Sven Rogge, CMM)

Technical info

These results were published in Angewandte Chemie for the MOF2020WEB special collection. For further information, please contact:

Ir. Sander Borgmans & prof. dr. ir. Veronique Van Speybroeck
Center for Molecular Modeling
Technologiepark 46, 9052 Zwijnaarde, Belgium
E sander.borgmans@ugent.be / veronique.vanspeybroeck@ugent.be

M  +32 (0)478 36 01 87