The importance of geometrical effects in the A dependence of many observables regarding antiproton annihilation on nuclei is expected on theoretical grounds. The cases of the charged pion multiplicity and of the frequency of the so-called single nucleon events are examined. In the first case. the respective roles of surface diffuseness, partial nuclear opacity, and pion absorption mechanism are examined. The possibility of extracting from comparison with experiment the average location of the annihilation site is critically discussed. The obtained values are in agreement with current theoretical estimates.

Experimental results on X-rays in antiprotonic Te, Sm, and Pt isotopes are presented. Attenuation of some lines due to the dynamic E2 mixing with nuclear rotational excitations was observed. The results are analyzed in terms of the p optical potential. Some effects of deformation are discussed. Previous findings such as a strong ls potential and the density dependence of the optical potential are confirmed.