Quantitative Impact of Occupation Smearing Methods on Conventional Superconductivity: from Electronic Structure through Lattice Dynamics to Electron-Phonon Coupling

In first-principles calculations of metallic systems, the discrete electronic mesh in the Brillouin zone necessitates a smearing function and its width (e.g., the widely used 0.02 Ry Methfessel-Paxton scheme) to enforce continuity of energy and occupation at the Fermi surface. However, the quantitat