Systematic studies of the structure and properties of liquid water at many temperatures and densities are performed by computer experiments on the basis of simple models. The observed anomalous properties of liquid water are reproduced semiquantitatively in radial distribution functions, thermodynamical quantities, self-diffusion coefficient and other quantities. The microscopic structures and its time dependences are studied and the lifetime of the local structure in the liquid water is estimated. [J. Cryst. Soc. Jpn. 26, 271 (1984) ] .
Thermal behaviors of cryptomelane (KxMn8O16 ; 0≤x≤2) have been examined with DTA and TGA. The differences in thermal decomposition of various cryptomelanes depend on the K-ions occupancy in its one-dimensional tunnels. Arising temperature from 630°C to 860°C, cryptomelane with lower occupancy is gradually converted to one with higher occupancy accompanied by producing bixbyite (Mn2O3) . After the tunnels are filled up with K-ions at 860°C, the cryptomelane is converted to bixbyite and K2Mn4O8 phase. Subsequently, the bixbyite is transformed to hausmannite (Mn3O4) . According to the above fact, cryptomelanes with various occupancies have been obtained by means of solid state reaction. [J. Cryst. Soc. Jpn. 26, 278 (1984) ] .