2 MEMBERS OF THE ABC-D6R FAMILY OF ZEOLITES - ZEOLITE-PHI AND LINDE-D

Linde D and phi, members of the ABC-double six-ring (ABC-D6R) family o f zeolites, have been studied by X-ray diffraction. Broadening of spec ific lines in the X-ray powder diffraction pattern is observed which i s consistent with the existence of faulting within the crystals. Both X-ray powder diffraction patterns can be simulated by introducing doub le six-member-ring sheet structural faults into the AABBCC stacking se quence of chabazite. These zeolites can be synthesised from a potassiu m-sodium-containing gel system in the absence of organic amines.