The aim of the first-principles approaches in quantum chemistry is to calculate the properties of molecules and crystals without the use of any experimental data. This calculation involves all atomic particles (the electrons and the nuclei), and the solution is simplified through the Born-Oppenheimer approximation. First, the electronic system is studied for different atomic configurations in order to calculate the potential energy surface and to find the optimized atomic positions corresponding to the minimal total energy per primitive cell. Quantum chemistry of solids concerns mainly those physical and chemical properties of solids that depend on the electronic structure, and they are always connected with the choice of the electronic Hamiltonian.
Two important issues of theoretical work, especially if heavy numerical efforts are involved, are the comparison with experiment, and the connection with simple models that allow us to extract the essential physical and chemical aspects of the system under investigation from the large amount of data. Therefore, we prefer to investigate simple, and more refined analytical mathematical models of systems and try to compute for real systems statistical and thermodynamic properties, using realistic potentials in the simulations.
Atomistic and coarse-grained models are used to explore the structure and mechanical properties of nanocrystals and bulk materials. These studies include atomic mobility, defect arrangements, dislocations, grain and phase boundaries as well as their role during deformation and fracture. Furthermore, our research spreads from modeling of sintering processes, to computation of electronic, magnetic, vibrational, optical, and thermal properties of solids.
These theoretical investigations are closely connected with the experimental work performed within our departments in the Center for Synthesis, Processing and Characterization of Materials for Application at Extreme Conditions (CEXTREME LAB), Institute of Nuclear Sciences “Vinča”, and University of Belgrade.
- D. Zagorac, J. C. Schön, J. Zagorac, M. Jansen, Theoretical investigations of novel zinc oxide polytypes and in-depth study of their electronic properties, RSC Advances 5, 33 (2015) 25929-25935, IF=3.289, ISSN: 2046-2069,DOI: https://doi.org/10.1039/c4ra16574h
- D. Zagorac, K. Doll, J. Zagorac, D. Jordanov, B. Matović, Barium Sulfide under Pressure: Discovery of Metastable Polymorphs and Investigation of Electronic Properties on ab Initio Level, Inorganic Chemistry 56(17) (2017), 10644-10654. DOI: https://doi.org/10.1021/acs.inorgchem.7b01617
- M. Čebela, D. Zagorac, K. Batalović, J. Radaković, B. Stojadinović, V. Spasojević, R. Hercigonja, BiFeO3 perovskites: A multidisciplinary approach to multiferroics, Ceramics International 43(1) (2017), 1256-1264.DOI: https://doi.org/10.1016/j.ceramint.2016.10.074
- D. Zagorac, J. Zagorac, M.B. Djukic, D. Jordanov, B. Matović, Theoretical study of AlN mechanical behaviour under high pressure regime, Theoretical and Applied Fracture Mechanics, 103, (2019), 102289. DOI: https://doi.org/10.1016/j.tafmec.2019.102289