  The calculation of molecular excited states is critically important to
decipher a plethora of molecular properties. In this manuscript, we develop an
equation of motion formalism on top of a bi-exponentially parametrized ground
state wavefunction towards the determination of excited states. While the
ground state bi-exponential parametrization ensures an accurate description of
the wavefunction through the inclusion of high-rank correlation effects, the
excited state is parametrized by a novel linear response operator with an
effective excitation rank beyond two. To treat the ground and the excited
states in the same footings, in addition to the conventional one and two-body
response operators, we introduced certain two-body "generalized" response
operators with an effective excitation rank of one. We introduce a projective
formulation towards the determination of the perturbed amplitudes for the set
of "generalized" operators. Our formulation entails a significantly small
number of unknown parameters and is shown to be highly accurate compared to
allied methods for several difficult chemical systems.
