Temperature dependence on the structure of Zundel cation and its isotopomers

摘要

Temperature dependence on the structural fluctuations of Zundel cation, H_5O_2 ~+, and its isotopomers, D_5O _2~+ and T_5O_2 ~+, have been studied using path integral molecular dynamics simulations in which nuclear quantum effect is fully taken into account. It has been found that the fluctuations of hydrogen-oxygen and oxygen-oxygen distances, which are relevant to the hydrogen bonded structure, grow drastically as the temperature increases within the range of investigation between 100 K and 900 K. The fluctuation with respect to the position of non-bonded hydrogen also increases substantially as the temperature increases. The temperature dependence on the fluctuation is greater for D 5O2 + or T_5O_2 ~+ than that of H_5O_2 ~+, since the zero-point effect of the former is less than the latter.