  Photoelectron Angular Distributions (PADs) resulting from 800 nm and 1300 nm
strong field ionization of impulsively aligned CF$_3$I molecules were analyzed
using time-dependent density functional theory (TDDFT). The normalized
difference between the PADs for aligned and anti-aligned molecules displays
large modulations in the high-energy re-collision plateau that are assigned to
the diffraction of back-scattered photoelectrons. The TDDFT calculations reveal
that, in spite of their 2.6 eV energy difference, ionization from the HOMO-1
orbital contributes to the diffraction pattern on the same footing as
ionization from the doubly degenerate HOMO orbital.
