  We have recently constructed compact, CNOT-efficient, quantum circuits for
fermionic and qubit excitations of arbitrary many-body rank [I. Magoulas and
F.A. Evangelista, J. Chem. Theory Comput. 19, 822 (2023)]. Here, we present
approximations to these circuits that substantially reduce the CNOT counts even
further. Our preliminary numerical data, using the selected projective quantum
eigensolver approach, demonstrate that there is practically no loss of accuracy
in the energies compared to the parent implementation while the ensuing
symmetry breaking is essentially negligible.
