HPW-21 – A Workshop of the IUCr Commission on High Pressure

We are all getting used to the new format of international meetings, which has been imposed on us since 2020 by the global pandemic. Despite missing personal contact and in-person communication, we have also learned how to benefit from the new situation. We have made meetings cheaper, enabling the participation of more people independently of their budget, and brought meetings to the individual scientists, targeting those unable to travel because of health, age, visa restrictions or very busy schedules. These benefits are exemplified by a recent Workshop organized by the IUCr Commission on High Pressure. This event was originally planned as a 'regular' event, just like all preceding events in this successful series of workshops organized around the world by the Commission every year, except for the IUCr Congress years. 2021 had been intended to be a non-Congress year, after the Congress in Prague in 2020, before the Corona-crisis arrived. The bid (Fig. 1) was approved by a majority vote of the IUCr Commission on High Pressure in 2019 in Vienna. A warm personal meeting in the cold and snowy, but sunny and shiny, winter of Novosibirsk, Russia, was anticipated for February 2021. The purpose of the Workshop is to bring together scientists working in the field of high-pressure crystallography to discuss the latest achievements in fundamental research, techniques and practical applications.

Figure 1. Preparing the bid for HPW-21 during an HP Commission Workshop in Vienna, Austria, in 2019. Left to right: Boris Zakharov, Elena Boldyreva and Nikita Bogdanov.

As it became clear that no in-person meeting would be possible in 2021, the organizers decided to change gear and opted for an online Workshop. Thus, HPW-21 became a reality and took place from 1 to 6 February. The number of participants (353) significantly exceeded that of all previous Workshops in the series, and so did the breadth of the geographical representation. Moreover, the online format encouraged an unusual, but highly inspiring, number of undergraduate and graduate student participants. The corresponding spread in the time zones challenged scheduling of the sessions; some participants were forced to start their working hours at 4 am, whereas others had to stay awake until 2 am for the evening sessions (Fig. 2).

Figure 2. Distribution of participants between (a) the countries and (b) the time zones.

The program of the Workshop included various activities. The IUCr Commission on High-Pressure Crystallography is celebrating its 25th anniversary in 2021. Therefore, the Workshop started with an introductory lecture dedicated to the history of the Commission presented by the Commission's first secretary, John Parise, on behalf of himself and the first Commission chair, Richard Nelmes. It was a real pleasure to recognize so many young faces of those who are now established researchers (Fig. 3) and to see how the Commission has matured with time.

Figure 3. The historic photos from the presentation by John Parise and Richard Nelmes dedicated to the 25th anniversary of the Commission on High Pressure.

Scientific program

The scientific program included the following sessions: High-pressure research at synchrotron facilities; High-pressure research at neutron facilities; Detectors, sample stages, heating systems, pressure cells; Superconducting and super-hard materials; New approaches to data processing and analysis; Macromolecular crystallography at high pressures; Pressure measurement and pressure scales; and Inorganic, coordination, organic, carbon and hybrid materials. Four Round Tables were organized, which triggered extensive and profound discussions: Data deposition and validation – state of the art (moderated by Kamil Dziubek and Simon Coles), High-pressure for advanced materials (moderated by Haozhe Liu), High-pressure for natural sciences (chemistry, physics, planetary sciences, life sciences) (moderated by Andrzej Katrusiak); and Сhallenges in instrumentation and techniques (moderated by Elena Boldyreva).

At the end of the Workshop a summary report from the Satellite Meeting "Towards national synchrotron infrastructure for high-pressure crystallography in Russia" was presented by Konstantin Litasov (Troitsk) and Sergey Rashchenko (Novosibirsk) – see the Satellite Meeting summary report below.

The first day of HPW-21 was dedicated to the instrumental and technical issues of high-pressure research. First, a general overview was given of the studies conducted at synchrotron and neutron sources, as well as those using laboratory instruments, presented by the Chair of the local organizing committee, Elena Boldyreva. Next, Mohamed Mezouar gave a detailed introduction to the new opportunities at the specialized high-pressure stations at the ESRF. This was followed by Frederico Alabarse, who illustrated the status of XPRESS – the dedicated high-pressure diffraction beamline at the ELETTRA synchrotron in Trieste. Nicola Casati presented the new possibilities for high-pressure science, which will be available after the machine upgrade to SLS-2.0 at the Paul Scherrer Institute at the Materials Sciences beamline, which will take place in 2024–2025. Denis Kozlenko gave an overview of the state-of-the-art neutron research at high pressures at the Joint Institute of Nuclear Research in Dubna (Moscow).

Further contributions described the new achievements in developing new detectors, sample holders, pressure cells, laser heating systems and other accessories presented by Almax easyLab (Koen De Hantsetters), DECTRIS Ltd (Tilman Donath, Baden-Dättwil, Switzerland), STOE & Cie GmbH (Thomas Pippinger and Jens Richter, Darmstadt, Germany), the Scientific and Technological Center of Unique Instrumentation (Pavel Zinin, Russian Academy of Sciences, Moscow, Russia) and the Jülich Centre for Neutron Science (Andreas Eich, Jülich, Germany).

During the following days the participants listened to lectures on the synthesis and structural characterization of metal superhydrides that become high-T_c superconductors at megabar pressures (Igor Lyubutin, Moscow, Russia, and Mikhail Kuzovnikov, Chernogolovka, Russia) and on new super-hard boron-rich chalcogenides (Vladimir Solozhenko, Paris, France). Nathalie Colloq'h (Paris, France) gave a general introduction to high-pressure macromolecular crystallography and also presented recent results from the group that was founded by a pioneer in this field, Roger Fourme. The methodology of obtaining high-pressure electron densities was discussed extensively in the contributions by Piero Macchi (Milan, Italy), Krzysztof Woźniak (Warsaw, Poland) and Krešimir Molčanov (Zagreb, Croatia). Matthias Krug (Münster, Germany) gave an overview of the challenges and perspectives in multigrain crystallography in multi-component systems.

A series of oral presentations over three days gave a broad overview of the fascinating high-pressure behavior of various compounds and materials, ranging from intermetallics and simple elements, through complex inorganic and organic synthetic compounds to minerals, materials and pharmaceuticals. The complete list of presentations is available at the HPW-21 site.

Particular attention at HPW-21 was devoted to educational aspects; a series of tutorials was offered alongside a dedicated session for young scientists. The tutorials included DAC handling and loading (Christophe Guillaume and Christophe Thessieu, Almax easyLab), EoSfit and data collection for precise lattice parameters (Ross Angel, University of Padova, Italy), High-pressure crystallization (Fatemeh Safari, University of Poznań, Poland), High-pressure data treatment with APEX software (by Tobias Stuerzer, Bruker); High-pressure data treatment in X-Area (Thomas Pippinger, STOE); and High-pressure data treatment in CrysAlis Pro (Fraser White, Rigaku Oxford Diffraction). Young scientists had a chance to present their work at a "Rising Stars" session as flash presentations, as well as during a poster session. Three posters were promoted by the Workshop Scientific Committee to be presented as oral contributions: Shir Ben Shalom (Beer-Sheva, Israel) "Anomalous pressure-dependent phase diagram of liquid Ga-In alloys"; Vishnu Vijayakumar Syamala (Nancy, France) "Evolution of halogen bonding interactions in a co-crystal system: Х-ray diffraction under pressure in the lab"; and Anastasiia Iskrina (Moscow, Russia) "P-V equation of state of new phase Ca(Fe,Al)O₄ up to 61 GPa".

Two posters received special awards. The "Rising Star Award on Advances in High-Pressure Science" from STOE was given to Viktoriia Drushliak (Poznań, Poland) for her work "Optical and structural high-pressure studies of Cs₄PbBr₆". The "Rising Star Award on Challenging high-pressure experimentation setup," sponsored by TechnoInfo and Rigaku Oxford Diffraction, was given to Amy Lazicki (Livermore, USA) for her work "Pb to 800 GPa using X-ray diffraction and laser ramp compression". Many of the contributors at the 'regular' oral sessions were also young early-career researchers.

Even though the Workshop was online, a virtual exhibition was organized. Manufacturers of high-pressure cells, detectors and modern diffractometers provided links to their sites, presented posters, and organized interactive webinars and user meetings. STOE also ran a quiz, and the winner was announced at the closing ceremony.

Social program

A social program was also provided. The participants were invited to make a virtual journey around Novosibirsk, Akademgorodok and NSU, viewing historical and modern photos of the city, and familiarize themselves with historical facts about the city and its famous people (such as Academician Mikhail Lavrentiev, the founder of Akademgorodok). During this virtual journey, participants were introduced to world-famous symbols of Novosibirsk, including the Trans-Siberian railway, Akademgorodok and the Opera and Ballet Theatre. The participants could then relax in the beautiful botanic gardens, and finished the excursion at the Arnold Katz Concert Hall listening to music or watching a ballet in the Opera and Ballet Theater. The links to the virtual excursions are still to be found at the HPW-21 site. Some movies are in English, some are silent and some are in Russian (with optional English subtitles). Recordings of some concerts, opera and ballet performances are also available at this link.

Acknowledgements

The whole enormous work has been done for free by a small but very efficient team from the Department of Solid State Chemistry at Novosibirsk State University, which included Boris Zakharov, Anna Gaydamaka, Nikita Bogdanov, Ivan Tumanov, Eugene Losev and Alexei Fedorov. Their enthusiasm and dedication made this event a real success. We also acknowledge the assistance of the IUCr Commission on High Pressure and of our industrial partners. Novosibirsk State University provided the access to Zoom for such a large number of participants.

Comments from participants

Comments posted by the participants following the conference were very positive, proving the first virtual HPW to have been a successful meeting. Some comments from participants are shown below:

Krzysztof Woźniak (Poland): "Thank you, Elena, for this excellent conference - really well done. I have enjoyed it very much - plenty of excellent and inspiring talks and discussions".

Nandini Garg (India): "At our place many of us were participating sitting in a conference room. So you can add on an average at least 10 more participants".

Viktoriia Drushliak (Poland): "Thank you all for organizing this Workshop! I learned a lot here, I am also grateful for the comments on my work, I have already found another space group for the second phase, as you suggested. I didn't expect to win the prize, because it is my first conference ever. You really encouraged me to move forward and work even harder! And thank you for making this Workshop free of charge, because probably I wouldn't have had an opportunity to attend it otherwise".

Piero Macchi (Italy): "I agree that online conferences give better opportunities, to present and discuss with a wider audience. Surely we would like to re-activate also the on site meetings, but should not just archive the online meetings. Thank you, Elena and all the co-workers in Novosibirsk and in the rest of the world (like Kamil), for excellent organization and inspiration".

Martin Ward (UK): "A big thank you to the organizers for this Workshop, it has been very enjoyable. Although we may have preferred to have travelled and met in person, the online platform does increase accessibility, and perhaps opens the possibility of having more regular meetings within the community, too?"

Kamil Dziubek (Italy): "Congratulations to Elena and the local committee! Thank you, it was a pleasure to stay with you all together this week. Perhaps we should think about hybrid conferences in the future to allow more people to participate. Even in the post-COVID world, we should also include those scientists who for various reasons cannot or are not allowed to travel".

Anna Krawczuk (Poland): "Thank you for the excellent quality workshop; it was extremely interesting and practical for someone who is just entering the field".

Sébastien Merkel (France): "Thank you everyone. The online workshop was good and allowed more attendance. It worked well for me".

Amy Lazicki (USA): "It has been a pleasure to hear from all of you, and thank you again, Elena, Boris, and the whole team."

Arthur Liu (USA, China): "Thanks, everyone! Congrats to the local organizing committee again for this wonderful Workshop!"

Alejandro Pedro Ayala (Brazil): "Thank you very much, Elena and the organizing committee, for the amazing conference."

Martin Fark (Germany): "Many thanks to all organizers and speakers, very well done!"

Manuel Fernandes (South Africa): "Thanks to everyone and especially to the organizing committee! I really enjoyed the conference".

Further information

A Book of Abstracts is available at the HPW-21 site.

A Virtual Special Issue – a collection of the original research and feature articles – will be published up until the end of 2021 in the IUCr journals IUCrJ, Acta Cryst. B, Acta Cryst. C, Acta Cryst. D, J. Appl. Cryst. and J. Synchrotron Rad.

The location and the terms of the next Workshop of the IUCr High-Pressure Commission will be selected by the High-Pressure Commission and announced later.

Towards national synchrotron infrastructure for high-pressure crystallography in Russia (Satellite Meeting report)

Modern synchrotron infrastructure is a key tool for state-of-the-art high-pressure crystallographic studies. Therefore, the national program for the development of synchrotron and neutron research and infrastructure – approved by the Russian government in 2020 – was met with a lot of enthusiasm in the Russian high-pressure community. The recent IUCr High-Pressure Workshop held online in Novosibirsk from 1 to 6 February 2021 provided us with a brilliant chance to organize a Satellite meeting of Russian groups that actively use synchrotron infrastructure for high-pressure research. The aim of the Satellite was to consolidate the community, discuss demands for high-pressure instrumentation and infrastructure at the future national synchrotron facilities, and coordinate further activities. The following institutions presented a review of their research directions and joined the discussion:

• Vereshchagin Institute for High Pressure Physics RAS, Troitsk (Konstantin Litasov)

• Shubnikov Institute of Crystallography RAS, Moscow (Igor Lyubutin)

• Institute of Earth's Crust SB RAS, Irkutsk (Igor Sharygin)

• Institute of Solid State Physics RAS, Chernogolovka (Mikhail Kuzovnikov)

• Novosibirsk State University (Elena Boldyreva)

• Saint Petersburg State University (Ljudmila Gorelova)

• Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk (Anna Likhacheva)

Colleagues from the Institute of Experimental Mineralogy RAS (Chernogolovka) and Kirensky Institute of Physics SB RAS (Krasnoyarsk), as well as representatives of the IUCr Commission on High Pressure and the EHPRG Committee (Kamil Dziubek and Boris Zakharov) also participated.

The research fields presented by participants spanned from high-temperature superconductivity, magnetism and high-pressure thermodynamics to phase transitions in planetary interiors and high-pressure crystallography of silicates and organic compounds, including molecular materials and pharmaceuticals; beam times for the corresponding experiments were provided by the most advanced high-pressure beamlines at SPring-8, ESRF, PETRA-III, APS, SLS, etc. After the presentations from the research groups, a report on the high-pressure X-ray diffraction opportunities at the future fourth-generation synchrotron source, SKIF (to be built in Novosibirsk, Russia), was presented by Sergey Rahchenko, a member of the SKIF Project Office. After discussion, a résumé was proposed as a result of the Satellite Meeting:

• Consider high-pressure community among key user groups for future national synchrotron sources

• Support the launch of high-pressure X-ray diffraction end-stations among first-stage beamlines of the future SKIF synchrotron source (Novosibirsk, Russia)

• Pay particular attention to user-friendly infrastructure for high-pressure research (DAC access, loading, heating, cryogenic and spectroscopic options, etc.) at SKIF

• Continue discussion on the development of large-volume press and nuclear resonant scattering (including high-pressure and low-temperature techniques) at SKIF at the future meetings

• Develop and promote university programs for future (high-pressure) synchrotron users.