Synthesis and crystal structure of zeolite W, resembling the mineral merlinoite

Zeolite W, K-10.3[Si21.7Al10.3O64]. 20H(2)O, was synthesized and the influences of excess alkalinity and the K/(K + Na) ratio on the synthesis products were studied. This synthetic zeolite is very similar to the mineral merlinoite. Its crystal structure was refined by the Rietveld method using X-ray powder diffraction data. The crystal structures of merlinoites from two locations and of two rather different synthetic zeolites of MER framework topology are known so far. Even though the chemistry of the pore filling is very different in the four compounds, the geometry and the density of their frameworks are remarkably similar.