Crystal structure of Li-analcime

Li-analcime Li1.69Na0.14[Al1.83Si4.17O12].2.05H(2)O has been prepared and s tudied by single-crystal X-ray structural analysis: a = 13.510(2), b = 13.5 20(1), c = 13.503(2) Angstrom, V = 2466.4(9) Angstrom (3), Z = 8, space gro up Pbca. The structure is compared with that of the starting Na-analcime. L ithium atoms lie near Na sires with a distorted octahedral coordination O-4 (H2O)(2). Due to the smaller si,e of Li atoms, their real environment is di fferentiated into 3+3 or 4+2. The off-network cations and the H2O molecules arf shifted from the sites which they, normally occupy in analcime irt a c ooperative manner. The changes in the unit cell dimensions and symmetry are explained from crystal-chemical viewpoint.