STRUCTURE OF D-2 IN ZEOLITE

We have measured the structure of D-2 adsorbed in zeolite 13X at tempe ratures in the range 5.5 to 80 K at a variety of fillings. We find tha t the D-2 molecules adsorb into well-defined adsorbtion sites in the z eolite structure. Two distinct adsorbtion sites, with binding energies on the order of 40 and 80 K, have been identified. No evidence for bu lklike liquid or solid behavior of the D-2 adsorbed in the pores has b een observed. Once the adsorbtion sites are saturated D-2 is no longer adsorbed into the pores and forms a bulk phase on the surface of the zeolite.