Theoretical and Computational Chemistry

The World Association of Theoretical and Computational Chemists [1] (WATOC) has held its world congress every three years since 1987, but the pattern changed unexpectedly in 2020. Planning for the 12th Triennial Congress of the World Association of Theoretical and Computational Chemists (WATOC 2020) in Vancouver in August 2020 was in the final stages when the World Health Organization declared COVID-19 to be a pandemic on 11 March 2020. It immediately became clear that WATOC 2020 would have to be postponed.

The Organizing Committee quickly determined that the chosen venue was available during only one week in July 2021. Delaying the Congress one year required corresponding with over 500 individuals: the presenters of 12 plenary lectures, 252 invited lectures and 180 invited communications, and the 60 session chairs. These speakers represented delegates from over 60 countries, with over 33% being women. Furthermore, dozens of contracts and commitments had to be renegotiated. Following the example of the 2020 Tokyo Olympics, and with the approval of the WATOC Officers, the Organizing Committee decided that the WATOC 2020 moniker and logo would remain the same, irrespective of the actual Congress dates.

By October 2020, planning was in the final stages for a second time and the abstract portal was reopened. The organizers were preparing to welcome more than 1200 participants. However, in January 2021 it became clear that WATOC 2020 could not proceed as an in-person event in July 2021. With the support of the WATOC Board to host the congress in-person, the Organizing Committee had to go through the challenging process of rescheduling once again.

The availability of vaccines in 2021 led to renewed optimism and consequently the Organizing Committee proceeded to plan WATOC 2020 for the third time. The Vancouver Convention Centre was only available during the week of 3-8 July 2022. In addition to conflicting with the July 4th Independence Day holiday which could limit the participation of some speakers from the USA, many original speakers and session chairs were unable to commit to the new dates. In fact, more than 100 of the 504 individuals identified in the preliminary program of April 2020 had to be replaced.

The Organizing Committee received many requests to make the congress a hybrid event. By late 2021 many large organizations, such as the American Chemical Society, had demonstrated that hybrid meetings could be successful. However, careful consideration of the logistics and financial implications led to the conclusion that WATOC 2020 would have to be an in-person event. Once again, the abstract portal was opened in October 2021.

In February 2022, the Organizing Committee announced that WATOC 2020 would proceed in July 2022 unless the circumstances made it impossible to proceed safely. At the time, there was still much uncertainty about the state of international travel and COVID-19 infection rates remained alarmingly high. The number of abstracts and registrants rose steadily during March and April, but it was not smooth sailing. For every two or three new abstracts and registrants, the Organizing Committee received a cancellation. Keeping accurate records was a challenge for the small number of organizers.

The organization of WATOC 2020 continued in a state of flux in May and June. In May, a draft program needed to be developed, which grouped submitted abstracts according to themes ranging from method development to biosystems, industry initiatives and quantum computing, to name just a few examples. Nevertheless, the number of withdrawals continuously escalated after the preliminary program was circulated to participants.

By mid-June the pocket program (a unique feature of WATOC Congresses) had to be designed and printed [2]. To keep a full program, Stacey Wetmore diligently dealt with daily cancellations, promoted authors of invited 10-minute communications to invited 20-minute lectures, and contacted and promoted early career researchers from posters to invited communications. All attempts were made to preserve diversity and maintain thematic sessions. At the same time, Alex Brown tackled the difficult task of securing and assigning session chairs.

Despite heroic efforts, it was impossible to secure speaker commitments before going to press. At the time of printing, the pocket program listed 12 plenary lectures, six of which were to be given by the 2018, 2019 and 2020 WATOC Medalists and an additional six by leading computational chemists chosen to provide an excellent representation of the many exciting subdisciplines. The chemical education session was scheduled to have two open discussion sessions as described below. Only one of the 252 invited lectures and five of the 180 invited communication slots were not filled in the pocket program. With the help of Krista Leroux and Zac Hawkins, the program was sent to the printer.

After the pocket program was finalized, many speakers had to make the difficult decision to cancel their attendance due to the ongoing impacts of COVID on health and travel. Problems arose from the inability to obtain visas due to overburdened government offices, COVID cases arising from other meetings, and delays or cancellations of international and domestic flights. Therefore, the on-line program was maintained by Stacey Wetmore as the most accurate record of events. Hourly changes were being made up to the eve of the 3 July Opening Ceremony and continued throughout the congress. While challenging, the efforts were rewarding as they provided many post-doctoral fellows the opportunity to showcase their research with a short talk at an international conference. In the end, 89% of the speaking slots remained occupied.

See photo album @ watoc2020.ca

On Sunday, July 3, 2022, the Opening Ceremony finally took place in the Vancouver Convention Centre amid much excitement and anticipation. For many of the 925 participants, it was the first in-person conference in over two years. The four plenary lecturers rose to the occasion with their outstanding presentations on many contemporary topics. The first day concluded with a well-attended and lively welcome reception.

WATOC 2020 featured three special symposia, two of which honoured legendary leaders in the field, while the third focussed on the teaching and chemical education aspects of computational and theoretical chemistry.

A full-day symposium honoured the late Tom Ziegler (1945 – 2015), a towering figure in the development of density functional theory (DFT) and its applications, and the original driving force behind Canada’s bid to bring the WATOC Congress to Vancouver. His seminal contributions spanned nearly five decades. He is known especially for his ground-breaking contributions to the chemistry and spectroscopy of heavy-metal complexes. Ziegler was amongst the earliest chemists to adopt/adapt DFT (he called it a Damned Fine Theory!). The symposium, organized by Dennis Salahub, followed the Plenary Lecture by Trygve Helgaker (Norway), and included 12 Invited Lectures and 10 Invited Communications with presenters from Canada, USA, Poland, Germany, The Netherlands, and France. As mentoring and fostering the careers of “next-generation” scientists was a constant preoccupation for Ziegler and recognized by the Canadian Society for Chemistry Tom Ziegler Award for “an outstanding early-career contribution to theoretical and/or computational chemistry,” several contributions were from early career researchers. The symposium demonstrated the breadth and the depth of Tom’s influence on theoretical and computational chemistry. He is deeply missed.

Wednesday morning began with an amazing pre-recorded 2018 Schrödinger Medal lecture by Klaus Ruedenberg and continued with a half-day symposium in his honour. The symposium was organized by Mark Gordon (Iowa State University), chaired by WATOC Past-President Leo Radom (University of Sydney), and included prominent collaborators, former students, and admirers of the honoree. Unfortunately, health considerations within the context of the pandemic prevented Professors Gordon and Ruedenberg from attending in person.

The participants took a break from the intense scientific program on Wednesday afternoon. About 500 went on a harbour cruise that included Coal Harbour, English Bay, and False Creek, while about 300 enjoyed some of the major tourist attractions in the Vancouver area, including Grouse Mountain, the Sea-to-Sky Gondola, the VanDusen Botanical Garden, and the Museum of Anthropology. The Congress banquet Wednesday evening featured an upbeat performance by the young musical troupe Showstoppers, a Canadian-centric trivia contest (won by two non-Canadians), and a very entertaining and thought provoking after-dinner talk by Don Weaver, a renowned computational chemist and neurologist from the University of Toronto.

The chemical education session started with an analysis of how the presence of computational chemistry in the Journal of Chemical Education has evolved over two decades. The marriage with laboratory experiments was noted as becoming far more common, a theme that continued throughout the session with examples that spanned a wide range of techniques.  Another two-decade perspective was given on how the importance of data and its management has been reflected in courses, evolving most recently into the coupling of electronic computational notebooks with modern FAIR data publication and the role of IUPAC in developing modern standards for these processes [3]. Subsequent talks focussed on many interesting topics, including how modern valence bond and molecular orbital theories are complementary in building electronic theories of molecules. Henry Rzepa (Imperial College) played a leading role in organizing the symposium and led the discussion periods, which were added due to last-minute cancelations.

The WATOC organizers were thrilled to receive 421 posters from students (undergraduate and graduate) and post-doctoral fellows, which were eligible for awards provided by PeerJ (peerj.com). To make the judging manageable, Alex Brown devised an innovative crowd-source approach whereby WATOC participants voted via a Google form for their top three posters in each session. The ten posters receiving the highest percentage of votes were selected for the poster awards, which were announced at the Closing Ceremony on Friday. The winners are entitled to a free publication in a PeerJ journal (subject to peer review) and a feature article about their research on the PeerJ blog site.

Additional posters were presented by faculty members and established researchers from industry and research organizations. The poster sessions were very well attended and continued past the 10 PM closing. Light refreshments nurtured the lively discussions of world-class science presented at WATOC [4]. The posters covered a broad spectrum of computational chemistry research including such diverse topics as artificial intelligence, atmospheric chemistry, catalysis, chemical biology, electronic structure theory development, quantum computing and quantum dynamics.

WATOC 2020 concluded on Friday with another four exceptional plenary lectures, including two by recent Dirac medalists which point to a very bright future for the discipline. The final lecture by Roald Hoffmann entitled, “Simulation versus understanding: A tension, and not just in our profession”, was an incredible tour de force presentation that left the audience with much to think about. Professor Hoffmann included Jean-Paul Malrieu as an author in recognition of their many discussions on the tension between simulation and understanding, including the moral implications of artificial intelligence. Following the invitation from Professor Trygve Helgaker to WATOC 2025 in Oslo, WATOC President Peter Gill (University of Sydney) closed the Congress with his inimitable elegant comments and reflections on WATOC 2020 and the future of our discipline. The challenges of organizing, hosting, and attending the congress will make this an event to remember for years to come.