团簇的第一原理分子动力学计算研究:价键优选法

First-principle molecular dynamics study of clusters:optimum valence bond scheme

根据团簇价键结构的特点 ,结合第一原理分子动力学模拟 ,提出价键优选法 ;可以在有限的计算量之下 ,得到其可计算的最大团簇体系Xm 的性质 ,以及所有团簇Xi(i<m)的性质 (例如其稳定几何构型、电子结构等 ) ,从而可以阐明团簇从小到大的几何构型演化规律 .以第二周期元素为例 ,阐明价键优选法 .十分有趣的是 ,甚至根据三原子团簇的性质 ,就已经能够看出相应元素的宏观性质 (如熔点、沸点 )随原子序的变化规律 .

We present an optimum valence bond scheme to study stable geometric structures of clusters, by combining the characteristics of valence bonds and the first - principle molecular dynamics simulation. With limited computational effort, we can obtain the properties of cluster X-m with m as large as possible, and the properties of all clusters X-i (i < m), e. g., their stable geometric structures, electronic properties, etc. Consequently we can elucidate the evolution law of clusters. We illustrate the optimum valence bond scheme with the second-row elements. The properties of three - atom clusters interestingly reflect the evolvement law with atomic number of macroscopic properties of corresponding elements (melting and boiling points).