摘要
针对Lennard-Jones(LJ)团簇的结构优化问题,在前人工作的基础上,提出了一个新的无偏优化算法,即DLS-TPIO(dynamic lattice searching method with two-phase local searchand interior operation)算法.对LJ2-650,LJ660,LJ665-680这666个实例进行了优化计算.为其中每个实例所找到的构型其势能均达到了剑桥团簇数据库中公布的最好记录.对LJ533与LJ536这两个算例,所达到的势能则优于先前的最好记录.在DLS-TPIO算法中,采用了内部操作,两阶段局部搜索方法以及动态格点搜索方法.在优化的前一阶段,内部操作将若干能量较高的表面原子移入团簇的内部,从而降低团簇的能量,并使其构型逐渐地变为有序.与此同时,两阶段局部搜索方法指导搜索进入更有希望的构型区域.这种做法显著地提高了算法的成功率.在优化的后一阶段,借用动态格点搜索方法对团簇表面原子的位置作进一步优化,以再一次降低团簇的能量.另外,为识别二十面体构型的中心原子,本文给出了一个简单的新方法.相比于文献中一些著名的无偏优化算法,DLS-TPIO算法具有较高的计算速度与成功率.
Based on the work of previous researchers,a new unbiased optimization algorithm,called dynamic lattice searching method with two-phase local search and interior operation （DLS-TPIO）,is proposed in this paper.This algorithm is applied to the optimization of Lennard-Jones （LJ） clusters with N=2-650,660,665-680.For each case,the putative global minimum reported in the Cambridge Cluster Database （CCD） is successfully found.Furthermore,for LJ533 and LJ536,the potential energies obtained in this study are superior to the previous best results.In DLS-TPIO,the interior operation,two-phase local search method and dynamic lattice searching method are adopted.At the initial stage of the optimization,the interior operation reduces the energy of the cluster,and makes the configuration ordered gradually,by moving some surface atoms with high potential energy to the interior of the cluster.Meanwhile,two-phase local search method guides the search move to the more promising region of the configuration space.In this way the success rate of the algorithm is increased significantly.At the final stage of the optimization,in order to decrease energy of the cluster again,the positions of surface atoms are further optimized by using dynamic lattice searching method.In addition,a simple new method to identify the center atom of icosahedral configurations is also presented.Compared with some famous unbiased optimization methods in the literature,DLS-TPIO has high computing speed and success rate.
出处
《中国科学：化学》
CAS
CSCD
北大核心
2011年第7期1137-1144,共8页
SCIENTIA SINICA Chimica
基金
国家自然科学基金(60773194
61070235)资助
