碱金属离子在汞金属界面吸附作用的量子化学研究

Quantum Chemistry Study of the Adsorption of Alkali Metal Cations on the Mercury Surface

应用量子化学方法对碱金属离子在汞金属界面的吸附作用进行了研究.选取汞金属界面的3个典型的位置（空穴、桥位和顶点）,采用MP2方法计算得到Li＋、Na＋、K＋3种离子在汞表面不同位置的吸附能.结果表明：3种金属离子都是在空穴位置有较大的吸附能,然后是桥位和顶点位置;对于平衡结构,从Li＋到Na＋和K＋,随着离子半径的增大,离子与汞金属界面的平衡距离在逐渐增大,吸附作用逐渐减弱,而且离子与汞之间的电荷转移在逐渐减小.

The absorption interactions between alkali metals cations and the mercury interface were studied by a quantum chemical method.Three typical sites of mercury interface,the hollow,bridge and top sites were chosen to calculate the adsorption energy with MP2 method.It is revealed that the hollow site has the largest adsorption energy,followed by the bridge and top sites.Moreover,as the ionic radius increases from Li＋ to Na＋ and K＋,the distance between the cation and the mercury interface increases,while the absorption energy gradually decreases,as well as the charge transfer between the cation and the mercury.