From 26 to 29 August, the Laboratory of Theoretical Physics at JINR hosted the first Molecular and Materials Modelling 2025 online school. The event brought together 28 senior students, postgraduates, professors, and scientific supervisors from universities in Iraq, Italy, Russia, South Africa, and Vietnam.

Example of modelling a simple periodic structure with calculated charge density

The intensive online course on modelling was conducted by employees of the BLTP Few-Body Systems Sector: a leading researcher Miroslav Iliaš and a senior researcher Dipayan Sen. “The aim of our online school is to create a solid educational foundation for the field of science known as computational molecular physics. Using simple molecular systems as examples, we demonstrate established theoretical methods based either on molecular mechanics or quantum mechanics of many atomic or many-electron systems, respectively” Miroslav Iliaš noted.

Classes were conducted via Zoom using open-source software. In addition, participants had the opportunity to watch recorded lectures. The online course was divided into two parts. In the part devoted to molecular modelling, the participants run the software and studied the electronic structure of atomic and molecular orbitals, geometry optimisation, and the spectroscopic, electric, and magnetic properties of various molecules. Some examples of practical tasks: calculating combustion enthalpy in a specific chemical reaction, computing properties of various elements, modelling a simple biomolecule.

The second part, materials modelling, included studying the Quantum ESPRESSO open-source software package and the atomic simulation environment in Python. The training was closely related to concepts such as:

• periodic boundary condition and space group;
• geometry optimisation: variable cell versus atomic relaxation;
• supercells and surface slabs;
• adsorption on surfaces at different physical scales: single atom, molecule, dimer, cluster;
• electronic and magnetic properties: density of states, band structure;
• charge density visualisation.

The practical part consisted of exercises and tasks, including advanced ones. Examples of tasks: calculating the total energy and relaxation of elementary cells of modifications of various chemical elements, calculating their electronic properties, density of states, and band structure, conducting convergence tests, and more.