A van Hove singularity (VHS) often significantly amplifies the electronic instability of a crystalline solid, including correlation-induced phenomena such as Hunds metallicity. We perform a systematic study on the interplay between Hunds coupling and electronic structures with a VHS focusing on Hunds metallicity. We construct a simplified tight-binding model targeting cubic perovskite materials and test the effects of the VHS utilizing dynamical mean-field theory with an exact diagonalization solver. The quasiparticle weight and the low-frequency power exponent of the self-energy provide a quantitative estimation of metallicity over the phase diagram. We find the VHS to substantially enhance Hunds metallicity. The results here suggest a range of parameters through which a VHS can bring great synergy with Hunds coupling.
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