  A theoretical framework for studying strong-field ionization of aligned
molecules is presented, and alignment-dependent ionization yields are computed
for CO2. Our calculations are in unprecedented agreement with recent
experiments. We find that the ionization process is affected by intermediate
resonance states, and the alignment-dependent ionization yields do not follow
the electron density of the initial states. The theory explains the breakdown
of semi-analytical theories, like the molecular tunneling theory and
strong-field approximation, were excited electronic structure is neglected.
