What if you could watch a chemical reaction happen, atom by atom? You would see bonds forming and breaking, molecules moving across surfaces, and tiny changes that can determine whether a reaction takes one path or another.
According to Prof Vasu Reddy, Deputy Vice-Chancellor: Research, Innovation and Postgraduate Studies, “Prof Moskaleva reminds us that the future of discovery belongs to those who can imagine what cannot yet be seen and then find ways to make it visible. It is clear that research excellence and all science begin with curiosity. Computational chemistry demonstrates a real transdisciplinary impulse. And this is when and where imagination, science, and technology converge to unlock new knowledge through experimentation and evidence. She reminds us that tiny particles are also able to tell a story about science. Her research transforms the invisible into insight, and complexity into understanding.”
Imagine and visualise
Her research focuses on computational chemistry, particularly on understanding chemical reactions and catalysis at the molecular level. “That understanding can help us design better catalysts,” she explained.
No single discipline can make this invisible world ‘talk’. Physics provides the laws of quantum mechanics that describe how atoms and molecules behave; mathematics provides the language to express those laws; and high-performance computers provide the power needed to perform the calculations.
This ability to turn an invisible process into something we can see also connects with the way chemists imagine their work. Prof Moskaleva traced this connection between science and imagination through the work of Nobel laureate Roald Hoffmann and his book Chemistry Imagined, exploring the parallels between art and science and the different ways both seek to make the invisible visible.
Artists use metaphor and imagery; scientists use models, equations, experiments, and increasingly, computer simulations.
One of the most fascinating aspects of this approach is what she calls ‘molecular movies.’ “As chemists, we tend to think in pictures. We are trying to imagine and visualise what we cannot see. Computational chemistry allows us to transform mathematical models into dynamic ‘molecular movies’ that reveal atoms moving, bonds forming and breaking, and catalytic reactions unfolding in real time,” she said.
Using a technique called ab initio molecular dynamics, researchers combine quantum mechanics with classical mechanics to predict how atoms move. The simulations are computationally demanding: a trajectory of around 100 picoseconds can take months and hundreds of thousands of computer core-hours to produce.
Creating these molecular movies also raises a bigger question: how much of reality do we actually need to capture? “Because the exact quantum-chemical description of complex molecules is mathematically intractable, chemists construct carefully designed approximations that retain the essential features of reality while remaining computationally feasible,” she pointed out.
Prof Moskaleva explains this with a simple example. If you are driving from Bloemfontein to Johannesburg, you do not need a map showing every tree and house along the way. You just need to know where the roads are. The same principle applies at the molecular level.
Choosing what to include in a model reflects a central theme of the lecture: the power of scientific models to make complex realities understandable.
Prof Moskaleva illustrated this approach through her work on nanoporous gold. Researchers can start with a simplified model, such as an ideal flat surface, and then progressively refine it to represent more realistic structures, including stepped gold-silver alloy catalysts. These increasingly detailed models allow researchers to investigate what happens at the atomic level without making the calculations impossibly demanding.
Studying nanoporous gold, resembling a nano-sponge with an enormous internal surface, she finds that although it looks like an ordinary piece of metal at a larger scale, its vast internal surface means that, catalytically, it behaves more like a high-surface-area nanostructured material. This allows it to act as a catalyst in reactions such as the conversion of methanol into methyl formate – an important bulk chemical.
Catalysts, she explained, are a little like the hidden machinery of the chemical industry. They make reactions happen faster and more selectively without being consumed themselves. “This means that a good catalyst can help us produce the same product using less energy and generating fewer unwanted byproducts, thus being more environmentally friendly,” she added.
Asking the right questions
From the ideas of the alchemists to the work of Copernicus, Einstein, and the development of quantum mechanics, scientific progress has repeatedly depended on imagining possibilities that could not yet be directly seen or measured.
The lecture also looked ahead to the growing relationship between computational chemistry, experiment, and artificial intelligence. As machine learning makes it possible to accelerate molecular simulations and explore increasingly complex systems, Prof Moskaleva argues that the role of the scientist remains much the same: to ask meaningful questions, examine evidence critically, and imagine new ways of understanding nature.
Ultimately, computational chemistry offers a way to ask questions of a world we cannot see – and then use models, mathematics, and computing to glimpse its answers.
“Innovation is not only about new technologies. As her lecture and continuing work demonstrate, catalysts accelerate chemical reactions, but outstanding researchers accelerate human progress through experiments, evidence, and creativity. Her inaugural lecture reflected the spirit of a research-intensive university. When molecules begin to ‘talk’, science becomes a language of possibility, revealing solutions to challenges we have yet to imagine” remarked Prof Reddy.