A. Loriso et al., COMPUTER-SIMULATION STUDIES OF ORDERED STRUCTURES FORMED BY RARE-GASES SORBED IN ZEOLITE-RHO, Journal of physical chemistry, 97(29), 1993, pp. 7665-7671
Computer simulations of the energies and structures of krypton and arg
on in zeolite rho at high sorbate loadings are reported here. The resu
lts, taken together with previous simulations of xenon, show that all
these gas atoms sorbed in the zeolite cages of diameter approximately
11 angstrom exhibit ordered structures at high loadings. The ordering
does not appear to be greatly affected by increases in temperature and
thus is most likely due to packing considerations. Several types of o
rder were observed, depending upon the size of the sorbate atom and th
e cage loading. Basically, all were of cubic symmetry, reflecting the
symmetry of the cages. Omitting the central sorbate atom that was usua
lly present, the structures can be described as simple cube (8 Xe atom
s), distorted face-centered-cubic (14 Ar or Kr atoms), and a more comp
lex but still cubic structure (20 Ar atoms). It is noted that cages of
this size are found in many zeolite crystals.