On June 26, 2025, Dr. Julia Westermayr, associated member at ScaDS.AI Dresden/Leipzig, participated in the WATOC Conference in Oslo, Norway. WATOC – The World Association of Theoretical and Computational Chemists – represents the largest international gathering in the field of theoretical chemistry. Such as Dr. Westermayr who holds the Junior Professorship of Artificial Intelligence in Theoretical Chemistry at Leipzig University. The congress in Oslo is the 13th in the WATOC series. 

The organizers of WATOC invited Dr. Westermayr to present her latest research on X-MACE. This method is an equivariant neural network that uses message passing based on atomic cluster expansion. It was originally developed by her PhD student Rhyan Barrett during an internship with Prof. Christoph Ortner at the Department of Mathematics at the University of British Columbia in Vancouver. It is an extension of the MACE framework to excited-state processes. These processes are important in areas such as photochemistry.

Machine Learning for Exited States

In her lecture “Machine Learning for Excited States”, Westermayr presented the first basic version of X-MACE and demonstrated its performance on a number of organic molecules. The associated paper Transferable Machine Learning Potential X-MACE for Excited States using Integrated DeepSets was published in February 2025. The method shows great potential for efficient screening of excited state dynamics – an essential step towards controlling dynamic processes in photochemistry. Achieving such control has long been a central goal in this field. However, due to the high computational cost in quantum chemistry, it remains unattainable. Moreover, the existing machine learning models for excited states have limited transferabilityX-MACE is designed to help overcome these limitations.

After attending a retreat with her working group in Zingst, Germany, which included hiking (sometimes even in the rain), Dr. Westermayr traveled directly to Oslo for the conference.

Throughout the conference, Dr. Westermayr participated in lively discussions and attended numerous stimulating presentations. She also had the opportunity to reconnect with many former colleagues and collaborators. Additionally, she engaged in insightful conversations with representatives from industry.

The WATOC conference concluded on Friday, June 27 with a series of plenary talks. Dr. Westermayr returned home on Saturday after an inspiring and productive week, rich in both scientific content and personal connections.