Introduction to the John Stanton special issue

The overriding theme of John Stanton's prestigious career has been the close collaboration between experiment and theory. This theme began early in John's academic training as a Ph.D. student in the group of W. N. Lipscomb at Harvard, after completing his undergraduate studies at the University of Michigan in 1984. Perhaps unlike many experimental chemistry and physics groups at the time, the Lipscomb group complemented work on protein x-ray crystallography with theory and computation. This theoretical streak led naturally to a collaboration with Rod Bartlett in Gainesville, where John quickly mastered the techniques of many-body quantum chemistry.

Upon obtaining his Ph.D., John joined the Bartlett group as a post-doc and later an assistant scientist. John's post-doc years were exceptionally productive, just as his graduate student years had been, with 24 high-quality papers published in three years. The project John initiated in Gainesville was the writing of a new code acesii which eventually replaced the original aces program of the Bartlett group. The concept, extending previous know-how, was mainly worked out by him and and other post-doc, Jürgen Gauss. This new version focused on efficient many-body perturbation theory and coupled cluster methods (along with their analytic gradients, properties, second derivatives, excited states,…), especially by combining vectorisation, at that time for the true vector machines of the '90s, with a particularly efficient handling of Abelian point group symmetry. These developments were especially prescient, as the techniques employed are still relevant on modern supercomputers and workstations alike.

During this period, John was joined by Jürgen Gauss and Péter Szalay, starting a pair of life-long friendships and collaborations, not the least leading ultimately to the transformation of the Mainz–Austin–Budapest version of acesii into the cfour package, which continues to lead development of a wide variety of coupled cluster methods.

In 1993, John started as an assistant professor at the University of Texas at Austin. John steadily rose through the academic ranks, culminating in the Watt Centennial Professorship from 2004 to 2016 and the William R. Kenan, Jr. Professorship at the University of Florida after his return in 2017. During this impressive academic career, John has so far earned many awards and recognitions, including NSF Young Investigator (1994), Sloan Fellow (1996), and Big XII Faculty Fellow (2005, 2008, 2015); a Frontiers in Spectroscopy Featured Lecturer (2007) and McElvain speaker at UW Madison (2012); and the John von Neumann Distinguished Award in STEM from the Fulbright Foundation (2021). John was elected to the International Academy of Quantum Molecular Sciences in 2009 and a Fellow of the American Physical Society in 2012.

John is also an outstanding educator and mentor. John's expressive and dynamic teaching style, dedication to his students, and his philosophy of continual improvement and course development have earned him the admiration of three decades of students. Additionally, John's teaching has been officially recognised many times: the Natural Sciences Teaching Excellence Award (1997, 2006) and Natural Sciences Foundation Advisory Council Award (2011), Regents Outstanding Teaching Award form the State of Texas (2011), member of the UT Austin Academy of Distinguished Teachers (2014), and Anderson Scholar Faculty Honoree (2017). John's mentoring efforts have played a critical role in helping his students and other young people in the field to foster their own research directions and succeed in academic careers. Many of John's postdocs and graduate students, including two of the authors, are now pursuing independent academic careers, with their research benefiting tremendously from John's insights and guidance.

Much of John's early independent work was focused on the development of many-body quantum methods. But over the years he has returned again and again to the theme of collaboration between experiment and theory, and has evolved into a truly interdisciplinary researcher with broad interests in physical chemistry/chemical physics, molecular spectroscopy and related fields. John is as often to be found working in a colleague's laser lab as in a computer lab; he is as likely to be seen scrutinising a spectrum as a piece of code; and attending one of his ‘group meetings’ one is as likely to hear about advances in microwave spectroscopy as in coupled cluster theory. John's attitude of deep appreciation for the symbiosis between theory and experiment is inspirational, and an important part of the reason why so many researchers on ‘both sides’ have been inevitably drawn into his orbit. ‘John's network’ includes a wide array of friends, collaborators and colleagues from around the world, including prominent and established researchers but also a great many young scientists to whom John provides unflappable support and guidance.

Of course, the other reason why John has been able to create such a network is his engaging and open personality. Undergraduates and full professors alike are invited to grab a beer and talk football, science, politics and more (although the undergrads may have to settle for a soda). Visitors get the special treat of Stanton Group Trivia Night. You'll often find students just hanging out in John's office outside of office hours. Just don't try and set up a lunch meeting, though, as John religiously skips lunch in favour of a good run.

It is in this spirit that we present a collection of articles in John's honour, authored by many of those selfsame people that John has touched and influenced over the years.

Acknowledgements

The authors would like to thank Audrey Stanton for creating the issue cover image, which celebrates John's many publications in Molecular Physics.