  We offer a theoretical and experimental study of the single-photon
photoionization of Ne III. The high photon flux and the high-resolution
capabilities of the Advanced Light Source at the LBNL were employed to measure
absolute photoionization cross sections. The resulting spectrum has been
benchmarked against high accuracy relativistic Breit-Pauli $R$-matrix
calculations. A large close-coupling wave function expansion which comprises up
to 58 fine-structure levels of the residual ion Ne IV of configurations
$2s^22p^3$, $2s2p^4$, $2p^5$, $2s^22p^23s$, $2s^22p^23p$ and $2s^22p^23d$ was
included. A complete identification of the measured features was achieved by
considering seven low-lying levels of Ne III. We found that the photoionization
cross-section ($\sigma_{PI}$) exhibits the presence of prominent resonances in
the low-energy region near the ionization thresholds that correspond to
low-lying levels. These include high-peak narrow resonances with almost zero
background introduced by relativistic effects. However, there does not exist a
significant contribution to $\sigma_{PI}$ from relativistic effects at the
high-energy interval of the present study.
