International School of Crystallography - Erice

Quantum Crystallography–ERICE 2025 – Final Report
directors: J. Contreras-García, P. Dominiak

The 61st Course of the International School of Crystallography on Quantum Crystallography (QCr) was successfully held in Erice, Italy, from May 30th to June 7th 2025. The school brought together a diverse and enthusiastic group of students and leading researchers in quantum crystallography, including experts in theoretical chemistry, materials science, and crystallography.

The school aimed to address an in-depth education in quantum-mechanical and crystallography methods, with special focus on methods specific to quantum crystallography. Participants gained a strong foundation for interpreting materials structure, properties, and response from a microscopic, quantum-informed perspective.

Scientific and Educational Programme

The programme featured lectures and workshops covering the following areas:

• Foundations: Origins of quantum crystallography; basic quantum mechanics concepts, the Hohenberg–Kohn theorem; basic theory of X-ray and electron diffraction; crystal dynamics
• Experimental Techniques: single-crystal high-resolution X-ray, neutron, and electron diffraction; Laue diffraction, polarized neutron diffraction, Compton scattering
• Theory Meets Experiment: Multipole model refinement, TAAM refinement, pseudoatom databases, Hirshfeld Atom Refinement, X-ray constrained wavefunction refinement, ELMOs, 1-electron reduced density matrix refinement
• Advanced Computation: periodic DFT; cluster-based quantum chemistry; crystal structure prediction
• Emerging Topics: artificial intelligence in crystallography, time-resolved crystallography
• Materials Properties: thermodynamics, magnetism, non-linear optics, high-pressure responses, and phase transitions
• Chemical Bonding: quantum topology, electron localization function, reduced density gradients
• Final Perspective Lectures on quantum crystallography in inorganic and bioorganic chemistry, material science and biology, historical and future perspectives of quantum crystallography
• Workshops provided hands-on software training, including diffraction data reduction, quantum calculations, chemical bonding analyses, various kinds of atomic and electronic crystal structure

The shared sessions with the Electron Crystallography School fostered rich interdisciplinary dialogue. These joint social events added a unique collaborative dimension to the week.

Student Experience

Most students came from a crystallography background, and the curriculum successfully introduced them to quantum mechanics and computational chemistry in a digestible and interactive format. The Marsala Room and meals served at poster area proved central to informal discussions—students highly valued the easy interaction with professors, who remained accessible throughout. A temporary dip in workshop attendance midweek was swiftly resolved by implementing an attendance list, after which full participation resumed.

During the final ceremony, the awards for the best posters were assigned: the first place was assigned to Elena Levina (Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, Milan, IT). The prize included a Springer eBook Voucher. The second poster prize went to Nilofar Kurawle (Consortium for Scientific Research Mumbai Centre, Mumbai, IN): this award included also a voucher for the IUCr journals online. Finally, the third place was convened to Lukas Seifert (Institute of Inorganic Chemistry, Aachen University, Aachen, DE).

The school also included a “Women in Science” discussion, reflecting our commitment to inclusivity. The session featured discussions of problems for women inclusivity in science initiatives, aligning with the effort to maintain a balanced speaker lineup.

Scientific Importance and Community Impact

Quantum crystallography is a fast-developing field at the intersection of theory and experiment. It enhances traditional crystallographic methods by offering a more detailed view of molecular and electronic structures through quantum chemistry, with profound implications for rational drug design, materials engineering, and chemical bonding analysis.

This school helped build bridges between traditionally separate communities of students—experimental crystallographers and computational theorists—by providing shared training and encouraging interdisciplinary conversation. As a result, participants left not only with stronger technical skills, but also with new collaborations and scientific perspectives.

To assess the outcome of the Course, participants were questioned through a survey to evaluate and comment on the scientific quality of the Course and the general organization. Their responses indicates that a similar meeting should be held at least in 3-4 years’ time. The 77% of the voting participants scores the course higher than 90/100.

Looking Ahead

Given the success of this edition, we are pleased to announce that the next edition of the on the International School of Crystallography on Quantum Crystallography is tentatively planned for eight years from now. The next school will be led by Anna Krawczuk and Alessandro Genoni, with support from Alison Edwards, ensuring continuity and innovation in future editions. We thank all lecturers, participants, and organizers for their dedication and enthusiasm, and we look forward to the next chapter of the School in Erice.

Poster prize 1st place: Elena Levina, Politecnico Milano, IT

Poster Prize 2nd place: Nilofar Kurawle (Consortium for Scientific Research, Mumbai, IN)

Poster Prize 3rd place: Lukas Seifert (Aachen University, DE)

The directors

Alex Eggeman, Mauro Gemmi, Tatiana Gorelik