元素簇合物Li_kAl_j（k，j≤3）的定域分子轨道研究

THE BONDING PROPERTIES FOR MIXED CLUSTERS Li_kAl_j (k,j ≤ 3)

在ａｂｉｎｉｔｉｏ３－２１Ｇ基下，用能量梯度法对ＬｉｋＡｌｊ（ｋ，ｊ≤３）的几何结构进行了优化，并在该构型和６－２１Ｇ基下采用Ｂｏｙｓ方法进行了定域化计算．结果表明，在ＬｉｋＡｌｊ簇合物中存在着双中心键、多中心键和孤对电子．同时还用成键性质对稳定性进行了讨论，认为用定域化能够对稳定性进行较好的解释．

At the level of ab initio 3- 21G, the equilibrum geometries of mixed clusters LikAlj(k,j ≤ 3) have been optimized by using energy gradient method. Under these geometries occupied canonical molecular orbitals(CMO) are localized with Boys localization method by using 6-21G basis set. The analysis of the properties of LMOs shows that there are two-centre,multi-centre,bending bonds and lone pair electrons in LikAlj.The relations between bonding properties and stabilities are disscussed. It is shown that the stabilities can be interpreted very well by bond order, multi centre bonds and the number of bonds.