  We demonstrate that charge-density-wave formation is possible via a purely
electronic mechanism in monolayers of the transition metal dichalcogenide
1T-VSe$_2$. Via a renormalization group treatment of an extended Hubbard model
we examine the competition of superconducting and density-wave fluctuations as
sections of the Fermi surface are tuned to perfect nesting. We find regions of
charge-density-wave order when the Heisenberg exchange interaction is
comparable to the Coulomb repulsion, and $d$-wave superconductivity for purely
repulsive interactions. We discuss the possible role of lattice vibrations in
enhancing the effective Heisenberg exchange.
