价键优选法及其在纳米结构预测与物性研究中的应用

本文论述价键优选法作为一种新颖的理论方法在材料结构预测与物性研究中的应用, 特别是在低维数纳米结构如团簇与纳米线研究中所展示的优势. 价键优选法以原子几何构型和电子云(主要是由费米能级附近的分子轨道组成, 即广义前线轨道)空间分布来合理决定纳米结构的稳定构型的选取. 本文以硅团簇为例说明价键优选法的特点, 以及锂、钠、铍、镁等金属团簇为例说明价键优选法在结构预测与材料 物性随尺寸演化规律研究中的应用, 以锂离子在MoS纳米线中的吸附为例说明价键优选法在储能材料离子传导研究中的应用, 最后总结价键优选法的进一步发展方向.关键词：价键优选法团簇纳米结构离子传导

Optimum valence bond scheme for its applications to the prediction of nano-structures and the study of matter properties

The optimum valence bond scheme is a new theoretical method in generating the initial geometric configurations in molecular dynamics simulations of cluster systems. We will present the application of such a new method to the prediction of nano-structures and the study of matter properties, especially for the low-dimensional nano-structures, such as clusters and nano wires. The optimum valence bond scheme uses the atomic geometry of structures and the space distribution of the valence electrons (mainly the molecular orbitals near the Fermi levels, i.e., the generalized frontier orbitals) to determine the possible stable geometric configurations of nano-structures. Silicon clusters are used to demonstrate the features of the optimum valence bond scheme. Metallic clusters such as those of lithium, sodium, beryllium and magnesium are used as examples to illustrate the application of the scheme to the prediction of structures and the studies of the evolution of the material properties with the sizes of clusters. We will use the adsorption process of lithium ion and MoS nano wire to illustrate the application of the optimum valence bond scheme in the studies of the ionic conduction mechanism of the energy storage materials. We will finish the paper by summarizing the direction for further development of the optimum valence bond scheme.
Keywords：optimum valence bond schemeclusternano-structureionic conduction