Effectiveness of smearing and tetrahedron methods: best practices in DFT codes

Density functional theory (DFT) codes are commonly treated as a "black box" in high-throughput screening of materials, with users opting for the default values input parameters. Often, non-experts may not sufficiently consider effect these parameters on prediction quality. In this work, we attempt to identify robust set related smearing and tetrahedron methods that return numerically accurate efficient results wide variety metallic systems. The effects total energy, number self-consistent field cycles, forces atoms studied two popular DFT codes: Vienna Ab initio Simulation Package (VASP) Quantum Espresso (QE). From nearly 40,000 computations, it is apparent optimal depends system, method, parameter, $k$-point density. benefit minor reduction which independent method or parameter. A large parameter -- what considered system dependent leads inaccurate energies forces. Bl\"ochl's small improvements energies. When treating diverse systems same parameters, suggest using little possible due dependence risk selecting gives