To calculate the band structure using hybrid functionals in Quantum ESPRESSO, you can follow these general steps:
Set up the input file: Prepare the input file in the Quantum ESPRESSO input format (typically using a text editor) for the specific system you want to calculate the band structure of. This includes specifying the crystal structure, unit cell parameters, atomic positions, and other relevant parameters.
Define the hybrid functional: In the input file, specify the hybrid functional you want to use. Quantum ESPRESSO supports various hybrid functionals, such as PBE0, HSE06, and B3LYP. This is typically done by specifying the appropriate exchange-correlation functional and setting the value of the mixing parameter.
Set the k-points: Define the k-point path along which you want to calculate the band structure. The k-point path is a set of high-symmetry points in the Brillouin zone that connect the valence and conduction bands. You can specify the k-point path manually or use tools like the seekpath library to generate it automatically.
Perform self-consistent calculations: Run a self-consistent calculation using the hybrid functional. This step ensures that the electronic structure is converged. Specify the appropriate convergence criteria, such as energy cutoffs, for the calculations.
Perform non-self-consistent calculations: Use the converged electronic structure obtained from the previous step to perform non-self-consistent calculations along the desired k-point path. This step calculates the band energies along the specified k-point path.
Analyze the output: Extract and analyze the band structure from the output files generated by Quantum ESPRESSO. The output typically includes the band energies and corresponding k-points along the specified path.
It's important to note that the specific details and input file format can vary depending on the version of Quantum ESPRESSO and the hybrid functional being used. It's recommended to refer to the official Quantum ESPRESSO documentation and user guides for the exact syntax and options required for your specific calculation.