粘土矿物分子片段Si_6O_(18)H_(12)、(Si_5AlO_(18)H_(12))^-和(Si_4Al_2O_(18)H_(12))^(2-)的计算研究

COMPUTATIONAL STUDIES OF MOLECULAR FRAGMENTS Si_6O_(18)H_(12),(Si_5AlO_(18)H_(12))^-AND(Si_4Al_2O_(18)H_(12))^(2-) OF CLAY MINERALS

采用最新的量子化学半经验计算方法MNDO－PM3，对作为粘土矿物结构基元的六元环分子体系进行了结构与能量的计算，揭示了结构变形的精确程度，并利用能量的差异大小，讨论了几种同分异构体的稳定性。

The MNDO-PM3 semiempirical molecular orbital method was used to compute the equi-librium geometries and energy differences in molecular fragments Si6O18H12, (Si5AlO182H12)- and (Si4Al2O18H12)2-, which are of great importance in clay minerals. Structural transformation of these clusters is accurately revealed by structural pictures obtained from calculation. The stability of some isomers of (Si4Al2O18H12)2- has also been discussed in terms of energy difference in this study.