  Downfolding coupled cluster (CC) techniques are powerful tools for reducing
the dimensionality of many-body quantum problems. This work investigates how
ground-state downfolding formalisms can target excited states using non-Aufbau
reference determinants, paving the way for applications of quantum computing in
excited-state chemistry. This study focuses on doubly excited states for which
canonical equation-of-motion CC approaches struggle to describe unless one
includes higher-than-double excitations. The downfolding technique results in
state-specific effective Hamiltonians that, when diagonalized in their
respective active spaces, provide ground- and excited-state total energies (and
therefore excitation energies) comparable to high-level CC methods. The
performance of this procedure is examined with doubly excited states of
H$_{2}$, Methylene, Formaldehyde, and Nitroxyl.
