  We discuss the mechanism by which the inclusion of multielectron polarization
improves the solution of the time-dependent Schr\"{o}dinger equation (TDSE) for
the oriented CO molecule in a strong external laser pulse within the
single-active-electron (SAE) approximation. A challenging problem of using the
SAE approximation is that the active electron, instead of undergoing
ionization, may be driven by the external field to lower-lying orbitals. For
the oriented CO molecule, dipole coupling to the lower-lying bound states of
the potential depends on the orientation angle, thereby affecting the
orientation-dependent ionization dynamics. By including multielectron
polarization, the external field is turned off within the molecular radius,
thereby minimizing dipole coupling of the highest occupied molecular orbital to
the lower-lying states of the potential. We discuss how turning off the
external field within an appropriate molecular radius without accounting for
the induced dipole term in the effective potential beyond this radial cut-off
distance, constitutes an effective and accurate approach to describe
strong-field ionization of CO and to minimize dipole coupling to lower-lying
bound states.

Atomic Physics