Distribution of extra-framework cations and water molecules in synthetic high-silica (Na, Cs)-rho-zeolite

We determined the distribution of extra-framework cesium and sodium atoms, as well as water molecules in the cavities of synthetic high-silica (Si/Al = 3.7) (Na, Cs)-rho-zeolite (Cs3.2Na6.7H0.3[Al10.2Si37.8O96] center dot 41H(2)O, Im-3m, a = 14.979(1) ) from X-ray powder diffraction data by applying the Rietveld and the maximum entropy methods. Extra-framework Cs and Na cations are found in alpha-cavities facing eight- and six-membered rings and in the center of the double aromatic ring D8R.