Abstract: The all-silica frameworks s lattice energy of a series of low-silica zeolites was determined by using the lattice energy minimization method. The results were compared to the lattice energy of dense polymorphs of SiO₂. All low-silica zeolites frameworks are only 43-68kJ·mol^-1 less stable thanα-quartz. This may imply that there is little energy barrier to the formation of lowsilica zeolites frameworks and explain the structural diversity observed for low-silica zeolites. The relationship of calculated lattice energies and framework structures was discussed. The results reveal that the lattice energy decreases and the relative stability of framework increases with the increase of framework densities. These XRD data of the low-silica zeolites contain very short Si-O bond length(0.1557nm), very long Si-O bond length(0.1764nm), and a large range of O-Si-O angles(93.38～133.41°), an average Si-O-Si angles close 144° and a larger range of Si-O-Si angles(127～180°).

Key words: low-silica zeolite, lattice energy minimization, bond length and bond angle, structrue and property