The structure of zeolite LZ-277
LZ-277 is a new aluminosilicate molecular sieve. It has an x-ray diffraction (XRD) pattern nearly identical to zeolite phi but with a much smaller pore size. Whether LZ-277 and phi-like materials are intergrowths or a physical mixture of phases has been a matter of debate. The ability to determine the structure of complex zeolites has been enhanced by HREM and, more recently, by the ability to simulate XRD patterns of faulted materials. In this study, the structure of zeolite LZ-277 is reported and confirmed by simulating the XRD pattern of this highly faulted material.The low magnification micrograph shows the faulted and intergrown disc morphology typical of this material (Figure 1). The faulting is most typically twinning on (001), and is shown in the [010] diffraction pattern (Figure 2). The pattern is indexed on an a = 1.38 nm, c = 1.50 nm unit cell and both lattice parameters and systematic absences are consistent with chabazite in space group Rm.