The main goal of the present project is to improve fundamental understanding of materials properties based on principles of quantum mechanics, and to provide this expertise to applied materials science, adjacent scientific disciplines, and to the industry. Therefore, the expected scientific output is of multidisciplinary relevance. The aim of the project is to reveal physics on the atomic level. It is the physics on this level that is to a large extend responsible for the novel properties of modern materials and vital processes taking place in real condensed matter systems employed by the modern society. The importance of the research we are going to conduct lies in that it should lead to new possibilities in improving materials performance and discovering qualitatively new materials required by a rapid technological progress. Particular subprojects included in the proposal are the application of our theoretical method to studies of dynamically disordered materials that are very promising in applications such as solid electrolytes for fuel cells and solid-state batteries, thermoelectrics, photovoltaics, and as barocaloric materials; and studies of novel lead-free halide double perovskites and the ways to improve their technologically important properties for optoelectronic applications.