[en] The Szilard-Chalmers recoil of the cations Rb⁺, Cs⁺, Ba²⁺, La³⁺, Co²⁺, Zn²⁺, Cu²⁺ and Na⁺ from the sodalite cage and hexagonal prism sites into the supercage sites of zeolites X and Y has been studied. This study is complementary to that described in Lai et al, JCS Faraday I; 72:181 (1976). It has been found that these cations recoil from the sodalite cage sites into the supercage sites with a probability of approximately 90% whereas the corresponding probability for these cations in the hexagonal prism sites (site I) is between 40 and 50% depending on the cation. It is thus possible to determine the preferences shown by these cations for these 'locked-in' sites as a function of temperature of calcination, Tsub(c), concentration and type of other cations contained in these sites. In these studies the cations present in the supercage sites before irradiation were usually NH₄⁺ but Ba²⁺, Ca²⁺ and Na⁺ have also been used. When Tsub(c) > 400⁰C, Rb⁺ and Cs⁺ began to populate site I. These ions populated this site in zeolite X at lower calcination temperatures than required for zeolite Y. When Tsub(c) was increased from 110 to 220⁰C the occupancy of site I by Ba²⁺ was greatly enhanced and when Tsub(c) > 440⁰C Ba²⁺ ions now occupied this site in preference to all other 'locked-in' sites. Barium exhibited a higher affinity for site I in zeolite X than in zeolite Y when Tsub(c) = 110⁰C. If dehydrated La-Y was assumed to have 5 La³⁺ ions per u.c. in site I, the hydration of this material did not change the concentration of La³⁺ in site I. Co²⁺, Zn²⁺ and Cu²⁺ ions all exhibited similar affinities for the 'locked-in' sites of zeolites X and Y. (author)