$\alpha$-cluster structure of $^{18}$O
  Background: Clustering phenomena in $N \neq Z$ nuclei provide an opportunity to understand the interplay between cluster and nucleon degrees of freedom.   Purpose:To study resonances in the $^{18}$O spectrum, populated in $^{14}$C+$\alpha$ elastic scattering.   Method: The Thick Target Inverse Kinematics (TTIK) technique was used to measure the excitation function for the $^{14}$C+$\alpha$ elastic scattering. A 42 MeV $^{14}$C beam was used to populate states of excitation energy up to 14.9 MeV in $^{18}$O. The analysis was performed using a multi-level, multi-channel R-Matrix approach.   Results: Detailed spectroscopic information, including spin-parities, partial $\alpha$- and neutron- decay widths and dimensionless reduced widths, was obtained for excited states in $^{18}$O between 8 and 14.9 MeV in excitation energy. Cluster-Nucleon Configuration Interaction Model calculations of the same quantities are performed and compared to the experimental results.   Conclusions: Strong fragmentation of large $\alpha$-cluster strengths is observed in the spectrum of $^{18}$O making the $\alpha$-cluster structure of $^{18}$O quite different from the pattern of known quasi-rotational bands of alternating parity that are characteristic of $N=Z$, even-even nuclei like $^{16}$O and $^{20}$Ne. 
M. L. Avila, G. V. Rogachev, V. Z. Goldberg, E. D. Johnson, K. W.   Kemper, Yu. M. Tchuvil'sky and A. S. Volya
nucl-ex