Resumo: Halide perovskites, with the general formula ABX3, have gained relevance in the field of solar cells due to their remarkable electro-optical properties, which enable efficient conversion of solar energy into electricity. Despite their promising characteristics, challenges such as long-term stability and structural complexity, their inherent soft nature, the high atom mobility (especially of the halides) and the unconventional dynamics of structural motifs (halide octahedra), demand exceptional
attention and dedication in research on these materials. Cesium lead halides (CsPbX3) are particularly promising due to its stability at high temperatures and desirable properties. However, CsPbX3 is temperature-sensitive and exhibits different phases at different temperatures. This theoretical study aimed to analyze the variation of the structure of CsPbBr3 perovskite as a function of temperature. To achieve this, Ab Initio Molecular Dynamics were performed in an NPT ensemble with a completely flexible cell, keeping the pressure and temperature constant. Multiple temperatures were considered, while the pressure was kept at zero in all simulations. The calculations were performed at the Density Functional Theory level using the CP2K software. The variations in various structural properties are calculated using long-time averages, which can be compared with experimental data obtained, for example, through X-ray diffraction techniques. Additionally, the influence of the material’s exposure time is investigated when calculating the system’s properties, allowing for a deeper understanding of perovskite stability at different temperatures. This work has been funded by FAPESP and by CNPq, through the Materials Informatics INCT.