  Sr$_2$MoO$_4$ is isostructural to the unconventional superconductor
Sr$_2$RuO$_4$ but with two electrons instead of two holes in the Mo/Ru-t$_{2g}$
orbitals. Both materials are Hund's metals, but while Sr$_2$RuO$_4$ has a van
Hove singularity in close proximity to the Fermi surface, the van Hove
singularity of Sr$_2$MoO$_4$ is far from the Fermi surface. By using density
functional plus dynamical mean-field theory we determine the relative influence
of van Hove and Hund's metal physics on the correlation properties. We show
that theoretically predicted signatures of Hund's metal physics occur on the
occupied side of the electronic spectrum of Sr$_2$MoO$_4$, identifying
Sr$_2$MoO$_4$ as an ideal candidate system for a direct experimental
confirmation of the theoretical concept of Hund's metals via photoemission
spectroscopy.
