Various Exchange-Correlation Effects on Structural, Electronic, and Optical Properties of Brookite TiO2

This work investigates the consequences of various exchange correlations on brookite titanium dioxide's (TiO2) structural, electronic, and optical properties. For the first time, statistical analysis of the obtained result compared to experimental data is done to find the best methods for numerous properties. It provides an in-depth study on brookite TiO2 by implementing OLCAODFTLBFGS algorithms along with GGA-PBE, GGA-PBES, GGA-PW91, GGA-BPW91, GGA-BP86, MGGA-TB09, and Hubbard U parameters to find out multiple properties. Investigated lattice parameters using GGA-PBES shows 0.43%, 0.56%, and 0.09% variation with experimental data, which further improved as 0.08%, 0%, and 0.21%, including Hubbard U parameter in the calculations. Eg using OLCAO-MGGA-TB09 shows no variations with the experimental value. Obtained range of absorption offers good agreement with experimental spectra. The statistical analysis using different methods for various properties described here can help find the best suitable ways for other materials. From the analyzed results, it revealed that GGA-PBES+U gives improved structural properties, whereas OLCAO-MGGA-TB09 gives an improvement in electronic properties. DFT provides good results for optical properties than DFT+U.