Watoc 2025
The 13th Triennial Congress of the World Association of Theoretical and Computational Chemists (WATOC 2025) was held at the Oslo Congress Centre from 21 to 27 June 2025. Hosted by the Hylleraas Centre at the University of Oslo, the congress brought together 1,098 participants and was among the largest and longest meetings ever organized in the field of theoretical and computational chemistry.
The scientific programme extended over all seven days of the week and comprised a total of 330 oral presentations and 627 posters. It included six plenary sessions, each featuring two speakers, for a total of 12 plenary lectures delivered in the main congress hall. In addition, the programme featured 75 thematic parallel sessions, each comprising four speakers, resulting in 300 presentations across five parallel streams. The sessions covered the full breadth of contemporary theoretical chemistry, from electronic-structure theory and spectroscopy to catalysis, materials, biosystems, machine learning, and qauntum computing. Three evening poster sessions, each with more than 200 contributions, were lively and well attended.
Half of the speakers in the parallel sessions were invited directly by the organizers, while the remaining speakers were selected on the basis of a competitive evaluation of more than 400 submitted abstracts. In total, 30% of all speakers at the congress were female, reflecting a conscious effort to achieve a balanced and inclusive scientific programme.
A major new feature of WATOC 2025 was Young WATOC, a pre-congress held on Saturday 21 June and dedicated to PhD students and early-career researchers who defended their theses in 2020 or later. From 102 submitted abstracts, 18 speakers were selected for the programme. The event attracted around 300 participants and concluded with a barbecue at Skullerudstua on the outskirts of Oslo.
Young WATOC, which was chaired by Hylleraas PIs Abril Castro and Ainara Nova, was highlighted by the WATOC president as a great success and will be continued at the WATOC 2028 in Mérida, Mexico.
WATOC 2025 attracted participants from 37 countries and about 230 institutions worldwide. Europe accounted for the largest share of attendees, followed by North America and Asia, with additional representation from Latin America, Oceania, the Middle East, and Africa. Students made up about one third of the participants, underlining the congress’s important role in education and early-career development within the field.
The congress was chaired by Trygve Helgaker and organized by the Hylleraas Centre in collaboration with the professional congress organizer Gyro Conference. The smooth daily operation of the meeting was strongly supported by the 33-member Hylleraas Crew, whose members provided technical and logistical assistance and helped create a welcoming atmosphere throughout the week.
A varied social programme complemented the scientific activities. Wednesday afternoon was reserved for excursions, offering participants guided tours of the National Museum, hiking trips in the surrounding hills, ferry excursions in the Oslo fjord, and guided historical walks in the city centre. The conference banquet, attended by nearly 700 participants and guests, featured Norwegian cuisine—including moose as the main course—along with speeches and musical entertainment, providing a memorable highlight of the congress week.
The congress concluded on Friday with the presentation of poster prizes, acknowledgements to organizers and the crew, and the formal introduction of WATOC 2028, to be held in Mérida, Mexico.
WATOC President Peter Gill praised the congress as “outstanding” and singled out Young WATOC as a particularly valuable addition that will shape future WATOC congresses.
WATOC President Peter Gill praised the congress as “outstanding” and singled out Young WATOC as a particularly valuable addition that will shape future WATOC congresses.
Program and photos
Contact
Trygve Helgaker, trygve.helgaker@kjemi.uio.no