Importance of nonuniform Brillouin zone sampling for <i>ab initio</i> Bethe-Salpeter equation calculations of exciton binding energies in crystalline solids
Antonios M. Alvertis, Aurélie Champagne, Mauro Del Ben, Felipe H. da Jornada, Diana Y. Qiu, Marina R. Filip, Jeffrey B. Neaton
Abstract
Excitons in solids often reside in a narrow region of reciprocal space. Yet, it is standard for first-principles exciton calculations to sample the entire Brillouin zone uniformly, at great computational cost and resulting in underconverged exciton binding energies. Here, the authors demonstrate that a straightforward-to-implement nonuniform sampling approach yields highly converged exciton binding energies, which can significantly differ from previous best theoretical estimates, at a fraction of the computational expense of uniform sampling approaches. This will enable the prediction of exciton binding energies of increasingly complex materials.