Including many-body effects into the Wannier-interpolated quadratic photoresponse tensor

We present a first-principles scheme for incorporating many-body interactions into the unified description of quadratic optical response to light noncentrosymmetric crystals. The proposed method is based on time-dependent current-density theory and includes electron-hole attraction \textit{via} tensorial long-range exchange-correlation kernel, which we calculate self-consistently using bootstrap method. By bridging with Wannier-interpolation independent-particle transition matrix elements, resulting numerical very general allows resolving narrow spectral features at low computational cost. showcase its potential by inspecting second-harmonic generation in benchmark zinc-blende semiconductor GaAs, layered graphitic BC$_{2}$N Weyl semimetal TaAs. Our results show that excitonic effects can give rise large sharply localized one- two-photon resonances are absent approximation. find overall good agreement available experimental measurements, capturing magnitude peak-structure spectrum as well angular dependence fixed photon energy. implementation Wannier-based code packages serve basis performing accurate theoretical predictions properties vast pool materials.