Organic and metal-containing compounds are important in medicine, catalysis, sensing and materials science. Their properties depend on molecular structure, metal coordination, hydrogen bonding, crystal packing, solvent and temperature. Experimental techniques such as X-ray crystallography, NMR and infrared spectroscopy provide valuable information, but computer simulations are often needed to explain the results and predict properties that cannot be measured directly. This project will use Gaussian, ORCA, CASTEP and GROMACS. Gaussian and ORCA will be used to study individual molecules, including their stable conformations, electronic structures, vibrational spectra, NMR parameters and interactions with biological targets. CASTEP will be used for periodic calculations of organic crystals and metal-coordinated materials. These calculations will examine crystal stability, proton positions, metal-coordination and spin states, vibrational properties, charge distributions and selected mechanical and electronic properties. The results will be compared with available crystallographic, spectroscopic and thermal measurements. GROMACS will be used to simulate molecular motion at different temperatures and under different environmental conditions. The simulations will investigate molecular flexibility, hydrogen bonding, solvation, hydration, diffusion, aggregation, crystal stability and interactions with proteins or formulation materials. Quantum-mechanical calculations will also help develop and validate the molecular models required for new organic and metal-containing compounds. Combining these methods will provide a clearer understanding of how molecular structure, chemical substitution, metal coordination and the surrounding environment influence the properties of the studied compounds. The results will support experimental interpretation, guide the selection of new compounds and contribute to scientific publications. HPC2N resources are required because the project involves many demanding calculations and long molecular-dynamics simulations that cannot be completed efficiently on an ordinary desktop computer. CPU nodes will be used mainly for quantum-mechanical and periodic calculations, while GPU nodes will be used for GROMACS simulations.