NCC Slovensko & NCC Poľsko: ORCA Hands-on Workshop

The workshop began with the registration and welcome of participants, followed by a presentation of the EuroCC 2competence center project. Instructor Klemens Noga from Cyfronet, the HPC center in Krakow, introduced the Polish HPC ecosystem and the opportunities available to users in the field of computational chemistry.

During the first day, the instructor focused on the practical aspects of setting up ORCA on HPC systems. Participants were introduced to the setup and operation of HPC clusters, best practices for installing ORCA, and the SLURM tool, which is used for managing computational tasks. They were familiarized with the structure and syntax of input files required for basic quantum chemical calculations, such as single-point energy calculations, property calculations, and geometry optimization. The workshop also covered output analysis, extraction of useful information, and visualization of results for better interpretation and presentation.

The second day began with more advanced computational options in ORCA. Participants learned how to set up calculations for vibrational frequencies, relativistic corrections, and spectroscopic properties. The instructor also focused on explaining scalability metrics, strategies for improving performance, and the efficiency of parallel computations on HPC systems, which the participants then practically tested. In the afternoon, participants worked on redox potential calculations and went through case studies prepared based on their own materials. The final part of the workshop dealt with troubleshooting calculations and sharing best practices to maximize the efficiency and accuracy of computations in ORCA.

The program also included a tour of the Devana supercomputer at the Computing Center of the Slovak Academy of Sciences. The event provided participants with fundamental knowledge and skills for working with the ORCA package in the field of quantum chemical computations on HPC systems. We believe the workshop was beneficial to the participants and assisted them in their work on their own research projects. The ORCA package is part of the software suite of the Devana system, and its license is freely available to all academic users.