The story of HTCC started with HTCC1 held in Šibenik in 2014, continued with the HTCC2 in Poreč 2017, and came to the point of no return with HTCC3 in Bol 2018. Just before the infamous pandemic, we had the HTCC4 – Structural biology workshop. HTCC series bounced back, as soon as the circumstances in the postpandemic world became favourable, with HTCC5 – another edition of HTCC entirely dedicated to macromolecular crystallography.

C. Bressler & M. Foerst, two men show at HTCC3.

HTCC1 was merely a pilot project, held as a central event to mark the IYCr2014 (International Year of Crystallography) in Croatia. It was envisaged as an overview of contemporary crystallography, from classical problems in chemical crystallography, all the way to macromolecular crystallography and charge density studies. We had the pleasure to enjoy lectures of the late Howard Flack, Elspeth Garman, Regine Herbst-Irmer, Dietmar Stalke, and Pete Wood from the CCDC. The following years (2015 and 2016) were the years of the major crystallographic events organized by the Croatian Association of Crystallography – ECM29 and ECS3. Therefore, the second edition of the HTCC had to wait until 2017 to be launched.

Henry Chapman’s Introduction to serial crystallography at HTCC4.

HTCC2 and HTCC3 were conceived as relatively heterogeneous mixtures of crystallographic hot topics, intended to provide a broader picture, while HTCC4 was entirely dedicated to biomacromolecular structural research. The list of distinguished lecturers who made honor to organizers by coming and teaching at the HTCCs is long, and many of them stayed with us for more than one edition of HTCC. Simon Parsons was there in the second and third editions, and Henry Chapman on the second and fourth. Both of them kindly accepted the invitation and became honorable members of the Croatian Association of Crystallographers.

Simon Parson explaning the principle of a (really) high pressure at HTCC2.

At the HTCC4, the organizing committee decided to experiment a bit by introducing complementary methods of cutting-edge macromolecular structural research (NMR, cryoEM) to the curriculum. It was a great success. The number of participants had beaten the HTCC records, and the profile of registered participants enabled the highest level of interactivity.

Elena Boldireva at HTCC3, always keen to explain and discuss.

The comprehensive one-day XFEL course, held majestically by Saša Bajt and Henry Chapman broadens the horizons of many of us in terms of cutting-edge crystallography achievements. 

Oliver Zerbe had an impressive one-man show on NMR in macromolecular structural research, which included lectures and round table discussions. Jürgen Plitzko and Carrie Bernecky gave an extensive overview of cryoEM, while molecular simulations were presented on the last day (as the HTCC4) by Franca Fraternally and Chris Oostenbrink.

M. Caffrey’s demo on LCP crystallization at the HTCC5.

The fifth edition – HTCC5  was held in Sheraton Dubrovnik Riviera Conference centre in Mlini, from 16th to 21st April 2023 and was entirely dedicated again to the macromolecular crystallography. The workshop gathered 52 registered participants from 16 countries (Algeria, Austria, Croatia, Czech Republic, France, Germany, Italy, Ireland, Jordan, Poland, Serbia, Sweden, Slovenia, Turkey, UK, and Ukraine) out of which 28 students, 11 lecturers, 7 sponsor representatives, 2 accompanying persons and 4 organizers.

Lecturers, students and participants of the pilot HTCC1, 2014 in Šibenik. The organizers in the front row joined by the president of the ECA Andre Roodt and Elspeth Garman